GB2067604A - A flat knitting machine particularly for the manufacture of intarsia products - Google Patents

Abstract

The invention is concerned with a flat knitting machine, for manufacturing intarsia products, of the kind which include cover shoes (18) which are mounted on thread guide bars (18) and limit the thread guide travel. To enhance the accuracy of this control the chains (10) used therein as operating means are mounted in side grooves (15) of the thread guide bars (16) to provide them with parallel runs (10a, 10b) which can be correlated in performance and include openings (27) for engagement by driver parts (19) coupling them to the cover shoes (18). <IMAGE>

Description

SPECIFICATION A flat knitting machine, particularly for the manufacture of intarsia products This invention relates to a flat knitting machine, particularly for the manufacture of intarsia products, which comprises a plurality of cover shoes, for limiting the thread guide travel, which are mounted on thread guide bars and adjustable by chain means.

Flat knitting machines of the kind set forth, with adjustable cover shoes for varying the thread guide travel, have already been proposed in DE-OS 15 85 375. The object of the present invention is to provide means for adjusting the cover shoes in a flat knitting machine of the kind set forth which are devised to ensure a very accurate adjustment.

This object is achieved by the invention, in a flat knitting machine of the kind set forth, in that each chain with two runs parallel to one another is mounted in a side groove in a thread guide bar and is equipped with lateral openings for the engagement therein of projections on at least one detachable driver part of a cover shoe.

By installing the chains in side grooves of thread guide bars, advantageously with a separator plate arranged in each case between the two parallel runs of the chain, not only have we provided a compact arrangement of the driving means, but any sagging of the chains is prevented.

As a result the relative movement of one chain element of one run can be exactly fixed in relation to a corresponding chain element of the other and parallel run; the same then applies to the relative positioning of the cover shoes coupled to these chain runs.

Advantageously the driver parts can be mounted for adjustment, in the longitudinal direction of the thread guide bar, in the associated cover shoe. The adjustment can be made progressively by means of an adjusting spindle.

With the accurate chain guidance in a flat knitting machine equipped in accordance with the present invention a progressive adjustability of the driver part in the cover shoe is moreover sufficient to provide a desirably fine adjustment of the cover shoe in its positioning on the needle bed. For this purpose the driver part can be provided with a toothed longitudinal edge engaged with a correspondingly-toothed tensioning bolt of the cover shoe.

The solution of the object set forth above can be enhanced if the flat knitting machine is equipped with a plurality of chains operated from a common drive mechanism mounted in separate grooves of one or more thread guide bars and including for each chain a pair of shafts rotating in opposite senses with each such shaft driven from a chain wheel of the common drive mechanism through a selectively-operable coupling.

Advantageously for this purpose use is made of an electrical rotary step pacer of a control assembly for the cover shoe adjustment which allows for a very accurate determination of the travel movement of the chain drive wheel and a correspondingly accurate control of the coupling.

Further features of the invention are set out in subsidiary claims below.

In illustration an embodiment of the invention will now be described with reference to the accompanying diagrammatic drawings. In these drawings: Figure lisa diagrammatic illustration of the travel of a chain for the adjustment of a cover shoe, this illustration comprising a partial side view of the two runs of an operating chain and a diagrammatic illustration of a driving mechanism common to a plurality of chains used in the system; Figure 2 a cross section through three parallel thread guide bars used in a flat knitting machine, these being provided with side grooves for receiving the chains for adjustment of the cover shoe; Figure 3 is a plan view and side views of a driving element for a cover shoe; Figure 4 comprises a partial plan view of a chain and a partial side view of an associated chain drive wheel;; Figure 5 is a partial longitudinal section on an enlarged scale, through the common driving mechanism taken along the line V-V of Figure 1; Figure 6 is a partial side view of a wheel of the common driving mechanism taken on the plane of the line VI--VI of Figure 5, including an electrical rotary stepping device of the control mechanism for the cover shoe adjustment; and Figure 7 is a diagrammatic partial side view of a pair of shafts with mechanism associated with a chain having driving wheels with magnetic coupling and magnetic brake.

Figure 1 illustrates the guidance in a flat knitting machine of a chain 10 having an upper run 1 Oa and a lower run 1 Ob. The chain is driven from a drive mechanism 11 which serves a plurality of chains in the machine, this mechanism being further described below.

The chain 10, which is endless, is passed over two reversing wheels 1 2 and 1 3 at one end of the flat knitting machine and a further reversing wheel 14 at the other end of the machine. Between the two wheels 12, 13 and the wheel 14 the two runs 1 Oa and 1 Ob of the chain are disposed parallel to one another in longitudinal side grooves 15, indicated in Figure 2, of a thread guide bar 16 of the flat knitting machine, this bar being of a form known per se. Between the two runs 1 Oa and 1 Ob is a separator plate 1 7.

Figure 2 shows three thread guide bars 16, 16' and 16", of which the bars 16 and 16' are provided at both longitudinal sides with a groove 1 5 for receiving a chain 10, whilst the thread guide bar 16' is provided at one side only with a longitudinal groove 1 5. Thus the flat knitting machine here concerned has five separate chains for adjusting the cover shoes to limit the travel of the thread guides. The five chains, and the five side or lateral longitudinal grooves provided therefor in the thread guide bars 16, 16', 16" are designated with the numerals 1-5 in Figure 2.

Figure 2 also shows a cover shoe 1 8 mounted on the thread guide bar 1 6 and a cover shoe 18' mounted on the thread guide bar 16'. Each of the two cover shoes 18 and 18' is provided with a driver part, 19 and 19' respectively, shown individually in Figure 3. The driver part 19 is in the form of a flat plate with toothed longitudinal edges 20 and 21, the teeth of which engage the teeth of a locking bolt 22, indicated In Figure 2, of the cover shoe 18, which has not been further illustrated. The driver part 19 is provided with two fixed driver pins 23 which stand upright from the plane of the plate and are arranged offcentre in such a way that they can be pushed into lateral openings in the chain elements of the upper run of the chain.By turning the driver part 19 through 1 800 in the plane of the plate the driver pins 23 can be brought into a position in which they can be inserted into the lateral openings of the chain elements of the other and lower run of the chain, as is shown in the case of the driver part 1 9 in Figures 2 and 3.

As can be seen from Figures 1 and 3 the chain 10 is in the form of a fleyer chain comprised of flat chain links 24. Thus, as shown in Figure 4, each second chain element is constituted by two spaced links 24 which can receive between them at each end the individual links 24 constituting the adjoining chain elements. An interspace 25 is left between the links of double link chain element and the teeth 48 of the chain drive wheel 49 can enter this. All the chain links 24 are of like construction and are provided with two outer holes for introduction of headless pivot bolts 26 and with a central larger hole 27 for the insertion of the driver pins 23 of the driver part 19.

The common drive mechanism 11 for all five chains of the flat knitting machine shown diagrammatically in Figure 1 includes an electric drive motor 28 which continuously operates an endless toothed belt 29 or an endless chain. This toothed belt 29, which is held tensioned by a roller 30, is guided over four pairs of shafts 31/32, 33/34, 35/36, and 37/38 in which the two shafts of each pair are driven in opposite rotational direction to one another. Associated with each pair of shafts is a chain of a plurality of particular chains. In the example illustrated in the drawing the pair of shafts 31/32 is associated with the two chains 1 and 5 (see Figure 2). The pair of shafts 33/34 is associated with the chain 2 and the pairs of shafts 35/36 and 37/38 are associated with the chains 3 and 4 (see Figure 2).All the pairs of shafts are arranged around a central spindle 39 with a pinion 40 arranged thereon engaging a rotatably mounted separate pinion 41 on the central spindle 39, this pinion 41 being rigidly connected in each case to a coaxial chain dlive wheel 50. The pinions 40 of the shafts 31-38 are selectively coupled through a magnetic clutch 42 with the associated and continuously driven shafts 31-38 and are subject to the action of a braking device 43, likewise magnetic, as is apparent from Figure 7.

The magnetic clutches 42 are programmed by means of an electric control assembly which is equipped with a rotator, seen in Figures 5 and 6, for each central pinion 42 and thus for each chain drive wheel 49. The central pinion 41 is provided for this purpose with plane toothing 44 the teeth of which cause the emission of a counting pulse when they pass a first detector head 45. A second detector head 46 responds to an additional single permanent magnet 47 arranged in the central pinion 41 and consequently puts out a counting pulse for each turn of the pinion 41. In the control assembly (not further illustrated) each counting pulse corresponds to a specific adjustment of the chain and thus the cover shoe coupled thereto. As soon as a specific number of pulses has been recorded at the detector 45 corresponding to a target pulse number, the magnetic clutch is cut off and the braking device 43 brought into action so that movement of adjustment of the cover shoe is abruptly terminated.

Claims (12)

1. A flat knitting machine, particularly for the manufacture of intarsia products, comprising a plurality of thread guides, cover shoes for limiting the travel of said thread guides and mounted on thread guide bars, and chains for adjusting said cover shoes, characterised by the fact that each chain has at least two runs thereof disposed parallel to one another in side grooves of a thread guide bar, and said chain has lateral openings for engagement by projections of at least one releasable driver part of a cover shoe.

2. A flat knitting machine according to Claim 1, characterised by the fact that a separator plate is arranged between two runs of the chain in the side groove of a thread guide bar.

3. A flat knitting machine according to Claim 1 or 2, characterised by the fact that at least one of the thread guide bars has a groove for a chain at both longitudinal sides.

4. A flat knitting machine according to åny of Claims 1 to 3, characterised by the fact that the chain is made up of links with lateral openings for insertion of driver pins of said driver part.

5. A flat knitting machine according to Claim 4, characterised by the fact that the chain is a flyer chain with links which are pivotally connected to one another by headless press-in pins, and that each link has centrally a coupling opening for a driver pin of the said driver part.

6. A flat knitting machine according to Claim 5, characterised by the fact that each second element in the chain is constituted by two spaced parallel links between which engages the tooth of a wheel driving the chain.

7. A flat knitting machine according to any of Claims 1 to 6, characterised by the fact that there are a plurality of driver parts and these are adjustable in the associated cover shoe in the longitudinal direction of the thread guide bar.

8. A flat knitting machine according to Claim 7, characterised by the fact that the driver parts are of plate form having two drive pins which stand out normally from the plane of the plate and are arranged eccentrically in relation thereto, suchwise that they can be inserted, in one position, in one run of a chain and, in a position rotated through 1 800 in the plane of the plate, in the other run of the same chain.

9. A flat knitting machine according to any of Claims 1 to 8, characterised by the fact that the driver part has at least one toothed longitudinal edge engaging with a correspondingly toothed locking bolt arranged in the cover shoe.

10. A flat knitting machine according to one of Claims 1 to 9, characterised by the fact that it comprises a plurality of chains mounted in separate grooves of at least one thread guide bar and are conducted over separate chain wheels of a common driving assembly, this latter having a common electrical drive motor which operates through a common endless drive belt for each chain, a pair of oppositely rotating shafts, and that each shaft of a pair of shafts is in driving engagement with the associated chain drive wheel through a selectively operable clutch.

11. A flat knitting machine according to Claim 10, characterised by the fact that at least one of the chain drive wheels of the common driving assembly is coupled to an electrical rotary stepping device of a mechanism for controlling the adjustment of the cover shoe.

12. A flat knitting machine substantially as herein described and as shown in the accompanying drawings.