GB2112026A - Stitch presser for flat knitting machine - Google Patents

Abstract

A stitch presser device for a flat knitting machine consists of slides adapted to act on the knitted fabric in the work zone, the device comprising at least two independent slides 14, 16 having differing cross-sectional shapes and associated with the same direction of displacement. These can be rendered operative or inoperative, as required, during the knitting process. The cross-sectional forms available permit the best possible use for all single-bed and double-bed types and sequences of knit that occur within a piece of material. <IMAGE>

Description

SPECIFICATION Stitch presser device for a flat knitting machine The present invention relates to a stitch presser device for a flat knitting machine with needle beds arranged in the form of an inverted V and with individuaily displaceable needles, the presser device being of the kind which is connected to work stations in the form of knit and stitch transfer stations formed by cam-boxes, and the presser device in its work zone consisting of operative slides which extend parallel to the work front of the needles.

Stitch presser devices of this kind are used on flat knitting machines of all types, their purpose being, on the one hand, to economise on the existing devices or weights for drawing off the knitted material to be fitted below the needle beds and, on the other hand, to render it possible to produce, economically, knitted pieces of correct form for clothing purposes, unusual structural patterns, or the like.

CH-PS 516.676,598.386 (580/80-4) disclose a number of stitch pressers, having slides of various cross-sectional shapes in the work zone.

In particular, round, oval, flat and triangular transverse sections, as well as a number of longitudinal sections of many shapes were described therein.

When using these stitch pressers, it has been found that round transverse sections, for example, are unsuitable for single-bed types of knit. On the other hand, flat transverse sections improve this type of knit without, however, ensuring that the stitches are perfectiy formed in the case of double bedded types of knit.

Combined cross-sections for slides, as described, for example, in CH-PS 592.763, provide results that are not completely satisiactory, since greatly differing types of knit, such as the single-bed and double-bed types, are frequently combined in one and the same article.

It therefore follows that the usual cross sections do not include a suitable shape that can be used in the same way to provide the best results for all types and sequences of knit that occur.

In addition, all of the existing systems suffer from the considerable disadvantage that the cross-sectional shape of the slides, must be fitted in the apparatus prior to the commencement of knitting, and a change can be made only when the machine is at a standstill.

This situation not only leads to longer stoppage times, but also greatly reduces the versatility of the machine.

The object of the present invention is to avoid the above-mentioned disadvantages of existing stitch presser devices.

According to the present invention there is provided a stitch presser device of the kind described above, wherein, for the same direction of displacement of the cam-boxes, at least two independent slides having differing cross-sectional shapes are associated with each work station, and in that one or other of the cross-sectional shapes of the slides can be optionally rendered operative or inoperative during the knitting process.

The subject-matter of the invention will now be described in greater detail by reference to an embodiment illustrated in the drawings, in which: Figure 1 shows a simplified view of part of a stitch presser device for a knitting system of a double-bed flat knitting machine, with slides of round and flat cross-sectional shape, Figure 2 is a sectional view along line Il-Il of Figure 1 , with a flat slide in operation, Figure 3 is a sectional view similar to that of Figure 2, but with a round slide in operation, Figure 4 is a diagrammatic representation of the positions of the slides depending upon allotment and direction of displacement.

In the stitch presser device illustrated in Figure 1 and for the purpose of rendering it easier to understand, the corresponding members of the front and rear needle beds are shown as being in the same plane of the drawing as indicated by the arrows A and B in Figure 2.

Furthermore, only those parts are shown that are necessary for explaining the present form of construction.

Two needle beds 1 and 2 (Figure 2), each having a verge bit 33, are arranged in the form of an inverted V on a machine bed, not illustrated.

Each needle bed has a plurality of slots 3, 4 in which needles 5, 6 are slidable. For the purpose of moving the needles, use is made of cam-boxes 7 ,and 8 accommodated in a common carriage 9 which moves in a reciprocating motion over the needle bed.

The actual stitch presser device extends along opposite inclined front faces of the carriage, and this device consists of two substantially identical parts 10 and 11. Part 10 of the device is connected by a base plate 12 to the front cam-box 7, and the part 11 thereof is similarly connected to the rear cam-box 8 by the base plate 13.

In the case of a single knitting system, the base plate 1 3 incorporates, for example, means for actuating slides 1 6 of a particular cross-sectional shape which, for the right-to-left direction of movement corresponding to the direction indicated by the arrow in Figure 1, also have means for actuating slides 14 having another cross-sectional form, and suitable for the left-to right direction of movement, i.e. in the direction opposite to that indicated by the arrow.

Further slides 1 5 and 1 7 are correspondingly arranged on the base plate 12 and their significance will be described hereinafter.

Arranged on each base plate 1 2 and 1 3 are horizontally disposed shafts 1 8 and 19, the precise level of which, in relation to the needle beds 1 and 2, is obtained by means of adjusting rods 20 and 21 and fixing blocks 22.

In order to provide the shafts 1 8 and 1 9 with different pivot positions, the adjusting rods 21 are shorter than the adjusting rods 20. A fixing screw 23 (Figure 1) permits fine adjustment to be readily made by rotating the adjusting rod.

Each shaft 18 and 19 is surrounded by a drumlike socket 24 and 25 which is mounted at each end by means of covers 26 and 27 and is laterally secured by circlips 28.

The slides 14 to 1 7 are firmly connected externally to the movable sockets 24 and 25, and in the zone of the needle beds 1 and 2, the slides have different cross-sectional shapes; also connected to the sockets are actuating pegs 29, which are disposed opposite the angled part of the slides.

The actuating pegs 29 are in contact with cams 30 and 31, which are mounted on bars 32 which are movable in unison.

A torsion spring 34, fitted between the shaft 1 8 and the socket 24 and a further torsion spring 34 fitted between the shaft 1 9 and the socket 25 cause the actuating pegs 29 to bear permanently against the associated cams 30 and 31, and at the same time cause the slides 14 to 17 to be resiliently supported on the knitted material which is located between the two needle beds 1 and 2.

As can also be seen from Figures 1 and 2, lateral displacement of each bar 32 and therefore of the cams 30 and 31 from a median position causes rotary movement of the sockets 24 and 25 and of the slides 14 to 1 7 in one or other of the directions indicated by the double-headed arrow.

The mode of operation of the described form of construction of the stitch presser device of the invention will now be described in detail by special reference to Figure 4.

The production of an article on a flat knitting machine usually begins with the starting courses of the knitted material in the form of a border, the needles of both needle beds coming into use.

For this purpose, use should be made of slides of round cross-sectional shape.

To this end, and for the impending movement of the carriage from right to left as indicated by the yarrow, the cams 30 and 31 of the front device have been brought into the left-hand position by means of a control programme, as shown in Figure 4a. This enables the slide 1 5 of round crosssectional shape to be swung into the work zone of the needles (Figure 3).

On the other hand, the cams 30 and 31 of the rear device remain in median position so as to hold the two slides 14 and 1 6 in the inoperative position.

On completion of the foreward movement of the carriage, the cam position is again changed for the impending return movement.

As illustrated in Figure 4b and in the direction indicated by the arrow, the cams 30 and 31 of the front device are now brought into the median position, and this has the effect of rendering the two slides 1 5 and 1 7 inoperative. The cams of the rear device, however, are moved to the right so as to release the slide 14 and to bring it into operation.

This process of engaging the disengaging the slides 14 and 1 5 of round cross-sectional shape in dependence upon the direction of movement of the carriage is repeated the desired number of times.

However, if a single-bed type of knit, for example, is to occur during the production of an article and only the needles of one needle bed are to be used, another cross-sectional form of the slides, i.e. a flattened form, becomes necessary.

Figures 4c and 4d show, in a similar manner, how the slides 1 6 and 1 7 are alternately brought into action depending upon whether the carriage is moved from right to left or in the opposite direction. The cams 30 and 31 are actuated in a similar manner.

Since the slides do not interfere with each other during their arcuate movement about the verge bit 33 as they do not move along common arcuate sections, the device may also be rendered completely inoperative.

The idea underlying the invention remains the same irrespective of whether single-system or multi-system flat knitting machines are involved, since all that is required is a corresponding extension.

It will of course be understood that a device of this kind is suitable not only for work stations for forming stitches, but that it may also be used for work stations for the transference of stitches or the like, that is to say, in all instances whe e different cross-sectional shapes of slides are used.

Claims (7)

1. A stitch presser device for a flat knitting machine with needle beds arranged in the form of an inverted V and with individually displaceable needles, the presser device being connected to work stations in the form of knit and stitch transfer stations formed by cam-boxes, and the presser device in its work zone consisting of operative slides which extend parallel to the work front of the needles, characterized in that, for the same direction of displacement of the cam-boxes, at least two independent slides having differing cross-sectional shapes are associated with each work station, and in that one or other of the crosssectional shapes of the slides can be optionally rendered operative or inoperative during the knitting process.

2. A stitch presser device according to claim 1, characterised in that allotment of the slides to the work stations takes palce at the points where the movement of the cam-boxes is reversed.

3. A stitch preser device according to claim 1, characterised in that the slides are controlled by a machine programme.

4. A stitch presser device according to claim 1, characterised in that each slide is secured to a holder in such manner that it executes an arcuate movement about a verge bit associated with the needle beds.

5. A stitch presser device according to claim 4, characterised in that each slide has its own pivot.

6. A stitch presser device according to claim 4 or claim 5, characterised in that the rotary movement of each slide is achieved by means of a helical cam face, which co-operates with a pin.

7. A stitch presser device for a flat knitting machine, substantially as hereinbefore described with reference to the accompanying drawings.