GB1558772A

GB1558772A - Stitch pressing device for knitting machine

Info

Publication number: GB1558772A
Application number: GB4795776A
Authority: GB
Original assignee: Edouard Dubied et Cie SA
Current assignee: Edouard Dubied et Cie SA
Priority date: 1975-11-25
Filing date: 1976-11-17
Publication date: 1980-01-09
Also published as: JPS5542168B2; DE2649387A1; JPS5266760A; IT1064611B; CH592763A5; BE848692A; FR2333069B1; FR2333069A1

Description

(54) STITCH PRESSING DEVICE FOR KNITTING MACHINE (71) We, EDOUARD DUBIED & CIE, (Societe Anonyme), a Swiss company of 2108 Couvet, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: The present invention relates to flat knitting machines of the kind comprising at least two needle beds arranged in inverted V fashion and provided with needles which can cross one another during their upward movement, a carriage arranged to move in a reciprocating motion over the needle beds and provided with at least one knitting system for the control of the needles during its movement in alternate directions, at least one stitch pressing device arranged to bear on the stitches held in the needle hooks and to move in synchronism with the knitting system for control of the needles, and means for alternately displacing the stitch pressing device between a position suitable for movement of the stitch pressing device in one direction along the needle beds and a further position suitable for movement of the stitch pressing device in the opposite direction.

In a flat knitting machine of this kind in which the stitch pressing device comprises two shoes or slides and the needles are controlled in tile two reciprocating movements of the carriage by cams fixed underneath the carriage, it is known to mount a device for the control of the stitch pressing device directly on the carriage so that one of the shoes or slides constituting the pressing element of the stitch pressing device operates when the carriage moves in one direction and the other shoe or slide operates when the carriage moves in the opposite direction.

It is also customary to provide a separate stitch pressing device for each feed, or each pair of feeds if knitting is performed on two needle beds.

It is also known to provide only one stitch pressing device for each feed, or each pair of feeds if knitting is carried out on two needle beds, and to change the position of the stitch pressing device at the end of each stroke of the carriage so that it. can operate successively in two opposite directions.

Stitch pressing devices comprise shoes or sides of different forms and sometimes include other elements such as rollers, wiper blades or brushes, but all have the disadvan image of not being usable for all knitted-fabric structures and in particular for mixed structures. One form of shoe, for example, can be used only for a limited range of stitch density and a selected structure. Moreover, the adjustment of a stitch pressing device is very difficult.

Stitch pressing devices equipped with rollers, wiper blades, brushes etc. have the disadvantage that there is a discontinuity of action on the knitted fabric in the sense that, as regards rollers, the space between the roller and the beginning of a shoe is not controlled.

According to the present invention there is provided a flat knitting machine of the kind described above, wherein the stitch pressing device comprises a main stitch presser in the form of at least one shoe and an auxiliary stitch presser arranged such that, in operation, the range of action of the auxiliary presser is at least partially superimposed on the range of action of the main presser, with the range of action of the auxiliary presser commencing in advance of the first crossover point of the needles, as seen in the direction of movement of the carriage.

and terminating before the end of the full ascent of the needles, and the cumulative width of the ranges of action of the main and auxiliary pressers is at least equal to the distance between the two needle beds.

The present invention enables the provision of a flat knitting machine having a stitch pressing device which can act in the space between the two needle beds irrespective of the thickness of the yarn or of the kind of knitted fabric, and thereby eliminate, at least partially, the disadvantages set out above.

The auxiliary stitch presser may comprise at least one tube having at least one nozzle for directing fluid, for example, compressed air or water, from the tube against stitches held in the needle hooks. Alternatively, the auxiliary stitch presser may comprise slides or shoes.

An auxiliary stitch presser utilising fluid preferable comprises two tubes or nozzles and a valve at the point of distribution of fluid between the tubes or nozzles, the valve being operable so as to direct fluid towards one main shoe or towards the other, according to whether the carriage is moving in one direction or in the opposite direction. It is advantageous for the fluid to be directed in a direction not perpendicular to movement of the carriage.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a partial view of a known stitch-pressing device for a two-feed flat knitting machine; Figure 2 is a front view of a stitch pressing device according to the invention; Figure 3 is a partial section on the line III--III of Figure 2; Figure 4 is a diagrammatic representation of the ranges of action of a shoe or slide and of the jets of compressed air with respect to the needle beds and the paths of the needles; Figure 5 is a section of the needle beds on a larger scale just in front of the crossover point of the needles; Figure 6 is similar to Figure 5 and relates to another knitted-fabric structure; Figure 7 is a front view of a modified construction according to the invention;; Figure 8 is a view in the direction VIII of Figure 7; Figure 9 is a representation similar to Figure 4, but of a modified construction according to Figure 7: Figure 10 is a section of the needle beds on a larger scale and of the shoes on the line X of Figure 7; Figure 11 is a section similar to Figure iO on the line XI of Figure 7 in the case of another knitted-fabric structure.

The stitch pressing device 1 shown in Figure 1 comprises two stitch pressers 2.

Each stitch presser 2 is composed of a shoe or slide 3 operating when the knitting car ridge moves from right to left on the knitting machine, and a shoe or slide 4 operating when the carriage moves in the opposite direction.

The stops 5 and 6 serve to reverse the stitch pressers when the carriage arrives at the end of its stroke.

The means for fixing the stitch pressing device to the carriage and the means for reversing the stitch pressers are known and are outside the scope of this invention; they are neither described nor shown.

The shoes 3 and 4 are fast with a support 7 which is itself fixed by known means (not shown) to the lever 8.

Figure 2 shows a stitch pressing device comprising a main stitch presser consisting of shoes 3, 4 as shown in Figure 1, the shoes 3, 4 being fast with a support 9 fixed to the lever 8, and also comprising an auxiliary stitch presser consisting of a tube 10 which terminates in two branch tubes 11, 12 for directing compressed air towards the shoes 3, 4.

The tube 1t,, or 12, shown in Figure 3 comprises a battle 13, which thus divides one end of the tube 11, or 12, to form two nozzles 14, 15. The feed of compressed air is effected through the flexible tube 16 connected on the one hand to the tube 10 and on the other hand to a device which may or may not be fixed to the knitting machine, adapted to supply the compressed air. This kind of device is known, but is outside the scope of this invention and is therefore not shown. Provision is made for mounting at the point of distribution 17 a valve enabling the compressed air to be directed towards the tube 11 or towards the tube 12, according to whether the carriage is moving from right to left or from left to right on the knitting machine.

The ranges of action 18 and 19 of the nozzles 14 and 15 respectively, are shown diagrammatically in Figure 4. The shoe 3 will have a range of action 20 shown between the two ranges of action of the nozzles.

The reference numbers 21 and 22 indicate the beginning and the end, respectively, of the range of action of the shoe 3.

The reference numbers 23 and 24 indicate the beginning and the end, respectively, of the ranges of action 18 and 19 of the nozzles 14 and 15.

The beginning 23 of the range of action of a nozzle is located in advance of the first point of intersection 25 of the needles, as seen in the direction of movement of the carriage, and this range terminates before the end of the full ascent of the needles in forming the stitch. The curves 26 and 27, respectively, shown in chain-dotted lines represent the paths of the hooks of needles operating in a front needle bed 28 and a rear needle bed 29, respectively, of a knitting machine.

The ranges of action 18 and 19 of the nozzles are superimposed on the range of action 20 of the shoe 3 in the sense that they commence and terminate after the commencement 21 and before the end 22 of the range of action of the shoe 3.

The cumulative width of the ranges of action is at least equal to the distance separating the two needle beds 28 and 29.

During knitting on two needle beds 28 and 29, the knitted fabric 30 is retained by the loops 31 in the hook 33 of the needles and by the loops 32 in the hook 34 of the needles.

The arrangement shown is that found just before the needles arc moved by the c2ms of the knitting carriage.

The shoe 3 presses on the knitted fabric 30 and the jets of compressed air 35 and 36 coming from the nozzles 14 and 15, respectively, press the stitches 37 and 38, respectively, against the needle beds 29 and 28, respectively. On the commencement of the upward movement of the needles, the loops 31 and 32 relax and the shoe 3, in conjunction with the jets of compressed air 35 and 36, presses the knitted fabric 30 downwardly so as to ensure that the loops 31 and 32 remain stretched. On the upward movement, the jets of compressed air 35 and 36 assist the loop 31, 32 to slide along the shank 33a, 34a of the needle.

The combination of the two elements, the compressed air and the shoe, permits careful dimensioning of the shoe so as to avoid too great a friction of the shoe on the stitch, which could cause irregular wales to appear on the knitted fabric, that is to say wales which would not be strictly straight. The same device can be employed when knitting on a single needle bed 29 of a two-bed machine. Figure 6 is a view similar to Figure 5, but in the case of knitting on a single needle bed. In this case, the action of the shoe 3 on the knitted fabric 39 is greatly reduced and it has a tendency to slide on the knitted fabric to position itself in the free space remaining between the knitted fabric 39 and the opposite needle bed 28.

On the other hand, the jet of compressed air 35 remains fully active and is sufficient to compensate for the lack of work supplied by the shoe 3.

It will thus be easily understood that such a device permits knitting on one and two needle beds in the same course of stitches or in different courses of stitches.

It may be advantageous to direct the fluid in a direction not perpendicular with respect to the movement of the carriage, so as to contribute towards a balancing if necessary of the stitches.

Figures 7 and 8 show another construction of stitch pressing device according to the invention This is composed of main shoes or slides 40, 41 and flexible auxiliary shoes or slides 42, 43, 44, 45. The main shoes 40, 41 are rendered fast by fixing means 46 with a support 47 which is fixed to the lever 8 by means which are known and not shown. The flexible auxiliary shoes 43, 45 are seated in grooves 48, 49 formed in a slide 50. They are positioned directly because of their shapes. The flexible auxiliary shoes 42, 44 are seated in identical manner in a spacer 51 and the whole assembly is secured by means of a cover 52 and fixing means 53. A compression spring 54 is supported on the one hand in the seat 55 of the slide 50 and on the other hand against the support 47.

The flexible auxiliary shoes 42, 43 and 44, 45, respectively, are profiled in such manner that they can be retracted on each side of the main shoes 40 and 41, respectively.

The ranges of action of the above-mentioned shoes in the space between the needle beds are shown in Figure 9.

The reference numbers 56 and 57 indicate the beginning and the end, respectively, of the range of action 58 of a main shoe 41.

The reference numbers 59 and 60 indicate the beginning and the end, respectively, of the ranges of action 61 and 62 of the flexible auxiliary shoes 45 and 44, respectively. The end 60 of the ranges of action 61, 62 of the said flexible auxiliary shoes is located, as seen in the direction of movement of the carriage, after the beginning 56 and before the end 57 of the range of action 58 of a main shoe 41. The ranges of action 61, 62. 58 are therefore partially superimposed.

The curves 63 and 64 represent the paths of the hooks of the needles operating on a front needle bed 28 and a rear needle bed 29, respectively, of a knitting machine.

The cumulative width of the ranges of action 61, 58, 62 is at least equal to the distance separating the two needle beds 28 and 29.

The ranges of action 61 and 62 of the flexible auxiliary shoes begin, as seen in the direction of movement of the knitting carriage, before the first cross-over point 65 of the needles and terminate before the full ascent of the needles.

During knitting on two needle beds 28, 29 (Fig. 10), the loops 31 and 32 are retained in the hooks 33 and 34, respectively, of the needles. The needles have not yet been moved up. The main shoe 41 presses on the knitted fabric 30.

The flexible auxiliary shoes 45 and 44 press against the needle beds 29 and 28, respectively, and on the loops 37 and 38, respectively, already formed. In order to arrive in this position, the flexible auxiliary shoes 45 and 44 have compressed the compression spring 54 by the displacement which they have produced in the slide 50. The ends of the flexible auxiliary shoes 44, 45 are just below the roof or inverted V formed by cross-over of the needles. In order to facilitate understanding of the drawing, the following needles, already moved up and partially moved up, are not shown.

According to Figure 11, during knitting on a single needle bed 29, the flexible auxiliary shoe 45 presses the knitted fabric 39 downwardly and against the needle bed 29.

and the flexible auxiliary shoe 44 and also the main shoe 41 serve as self-centring elements for the shoes in the space between the needle beds. The slide 50 (Fig. 7) is in the low position under the action of the compression spring 54.

Thus, it will be easily understood that, with such a device, it is possible to knit structures on one or two needle beds and even mixed structures in the same course.

A mixed structure will cause a reciprocating movement of the slide 50 enabling it to adopt the position. according to Figure 10 or according to Figure 11, depending on whether the flexible auxiliary shoes 45, 44 are in a zone of knitting on two needle beds (Fig. 10) or on one needle bed (Fig.

11).

The knitter thus has in his hands a simple device enabling him to increase greatly the range of application of stitch pressing devices. He has at his disposal a system selfadjustable in width which no longer depends on the structure of the knitted fabrics. He thus has a device operating throughout the space separating the needle beds and, above all, very close to them.

WHAT WE CLAIM IS:- 1. A flat knitting machine comprising at least two needle beds arranged in inverted V fashion and provided with needles which can cross one another during their upward movement, a carriage arranged to move in a reciprocating motion over the needle beds and provided with at least one knitting system for the control of the needles during its movement in alternate directions, at least one stitch pressing device arranged to bear on the stitches held in the needle hooks and to move in synchronism with the knitting system for control of the needles, and means for alternately displacing the stitch pressing device between a position suitable for movement of the stitch pressing device in one direction along the needle beds and a further position suitable for movement of the stitch pressing device in the opposite direction, characterised in that the stitch pressing device comprises a main stitch presser in the form of at least one shoe and an auxioperation, the range of action of the auxiliary stitch presser arranged such that, in liary presser is at least partially superimposed on the range of action of the main presser, with the range of action of the auxiliary presser commencing in advance of the first crossover point of the needles, as seen in the direction of movement of the carriage, and terminating before the end of the full ascent of the needles, and the cumulative width of the ranges of action of the main and auxiliary pressers is at least equal to the distance between the two needle beds.

2. A flat knitting machine as claimed in claim 1, characterised in that the auxiliary stitch presser comprises at least one tube having at least one nozzle for directing fluid from the tube against stitches held in the needle hook.

3. A flat knitting machine as claimed in claim 2, characterised in that the auxiliary stitch presser comprises two tubes or nozzles and a valve at the point of distribution of fluid between the tubes or nozzles.

4. A flat knitting machine as claimed in claim 2 or 3, characterised in that the auxiliary stitch presser is arranged to direct fluid in a direction not perpendicular to the movement of the carriage.

5. A flat knitting machine as claimed in any of claims 2--4, characterised in that the fluid is compressed air.

6. A flat knitting machine as claimed in any of claims 2-4, characterised in that the fluid is a liquid, for example water.

7. A flat knitting device as claimed in claim 1, characterised in that the auxiliary stitch presser comprises at least one flexible shoe mounted on a slide and resilient means for urging the slide in a direction towards stitches held on the needle hooks.

8. A flat knitting machine as claimed in claim 7, characterised in that the resilient means comprises a spring.

9. A flat knitting machine having a stitch pressing device substantially as hereinbefore described with reference to Figures 2-6 or Figures 7-i 1 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

the main shoe 41 serve as self-centring elements for the shoes in the space between the needle beds. The slide 50 (Fig. 7) is in the low position under the action of the compression spring 54.

Thus, it will be easily understood that, with such a device, it is possible to knit structures on one or two needle beds and even mixed structures in the same course.

A mixed structure will cause a reciprocating movement of the slide 50 enabling it to adopt the position. according to Figure 10 or according to Figure 11, depending on whether the flexible auxiliary shoes 45, 44 are in a zone of knitting on two needle beds (Fig. 10) or on one needle bed (Fig.

11).

The knitter thus has in his hands a simple device enabling him to increase greatly the range of application of stitch pressing devices. He has at his disposal a system selfadjustable in width which no longer depends on the structure of the knitted fabrics. He thus has a device operating throughout the space separating the needle beds and, above all, very close to them.

WHAT WE CLAIM IS:- 1. A flat knitting machine comprising at least two needle beds arranged in inverted V fashion and provided with needles which can cross one another during their upward movement, a carriage arranged to move in a reciprocating motion over the needle beds and provided with at least one knitting system for the control of the needles during its movement in alternate directions, at least one stitch pressing device arranged to bear on the stitches held in the needle hooks and to move in synchronism with the knitting system for control of the needles, and means for alternately displacing the stitch pressing device between a position suitable for movement of the stitch pressing device in one direction along the needle beds and a further position suitable for movement of the stitch pressing device in the opposite direction, characterised in that the stitch pressing device comprises a main stitch presser in the form of at least one shoe and an auxioperation, the range of action of the auxiliary stitch presser arranged such that, in liary presser is at least partially superimposed on the range of action of the main presser, with the range of action of the auxiliary presser commencing in advance of the first crossover point of the needles, as seen in the direction of movement of the carriage, and terminating before the end of the full ascent of the needles, and the cumulative width of the ranges of action of the main and auxiliary pressers is at least equal to the distance between the two needle beds.
2. A flat knitting machine as claimed in claim 1, characterised in that the auxiliary stitch presser comprises at least one tube having at least one nozzle for directing fluid from the tube against stitches held in the needle hook.
3. A flat knitting machine as claimed in claim 2, characterised in that the auxiliary stitch presser comprises two tubes or nozzles and a valve at the point of distribution of fluid between the tubes or nozzles.
4. A flat knitting machine as claimed in claim 2 or 3, characterised in that the auxiliary stitch presser is arranged to direct fluid in a direction not perpendicular to the movement of the carriage.
5. A flat knitting machine as claimed in any of claims 2--4, characterised in that the fluid is compressed air.
6. A flat knitting machine as claimed in any of claims 2-4, characterised in that the fluid is a liquid, for example water.
7. A flat knitting device as claimed in claim 1, characterised in that the auxiliary stitch presser comprises at least one flexible shoe mounted on a slide and resilient means for urging the slide in a direction towards stitches held on the needle hooks.
8. A flat knitting machine as claimed in claim 7, characterised in that the resilient means comprises a spring.
9. A flat knitting machine having a stitch pressing device substantially as hereinbefore described with reference to Figures 2-6 or Figures 7-i 1 of the accompanying drawings.