GB2138847A

GB2138847A - Electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine

Info

Publication number: GB2138847A
Application number: GB08410537A
Authority: GB
Inventors: Shinji Togo; Yoshiki Kurita; Keizi Shimizu
Original assignee: Nagata Seiki Co Ltd
Current assignee: Nagata Seiki Co Ltd
Priority date: 1983-04-26
Filing date: 1984-04-25
Publication date: 1984-10-31
Also published as: IT8420691A0; GB8410537D0; JPS6238463B2; IT8420691A1; GB2138847B; IT1173582B; JPS59199850A

Abstract

The apparatus has a plurality of a needle selecting levers (8) each of which is pivotally mounted (at 7) intermediate its ends and has a first end (81) arranged to engage a butt (36) on a needle selecting jack (3) mounted on a needle cylinder (1). The opposite second end (83) of each lever (8) carries a row of permanent magnets (15,16,17) with adjacent magnets being of opposite polarity. An electromagnetic device (20) having a core (25) which carries a coil (22, 23) is arranged adjacent the permanent magnets (15, 16, 17) and by appropriate energisation of the coil (22, 23) to reverse the polarity of pole faces (241, 251) the lever (8) can be pivoted between an operational position in which its first end (81) engages a butt (36) of a jack (3), and a non- operational position. The lever ends (81) may effect a lifting action as shown or a pressing action on the butts. In an alternative embodiment the levers pivot about horizontal axes instead of the vertical axis (7). <IMAGE>

Description

SPECIFICATION Electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine This invention relates to an electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine, such as hosiery knitting machine, and more particularly to such on apparatus applied to multiple jacks which are used in a jack lifting up system and in a jack press system, as elements for selecting needles to pattern knitted goods produced on a needle cylinder.

In conventional patterning mechanisms of circular knitting machines several kinds of electromagnetic needle selecting apparatus are known. There are two particular mechanisms for selecting needles, one is a single jack mechanism and the other is a multiple jack mechanism, and there are two methods of selecting a needle, one is a jack press method and the other is a jack lifting up method. The single jack mechanism for selecting a needle is used with only the jack press method in which each needle is selected by an electromagnetic device, and thus there is the limit to the speed of selecting the needle, the limit being 1.2 millisecond to select one needle.On the other hand, the multiple jack mechanism for selecting needles is used with the jack press method or the jack lifting up method, but in both methods it is difficult to manufacture the necessary precise parts and to assemble them due to the complexity of the construction, and it is very expensive, due to difficulty in control and adjustment, to maintain the required high level precision and accuracy thereof. In addition thereis a problem in the needle selecting speed in that the moving time of a needle selecting lever can not be significantly reduced.

In any jack press method or jack lifting up method with a multiple jack mechanism, the time to operate a butt of a jack with a needle selecting lever is fixed. In order to increase the speed of selecting the needle, the number of butts on the jack must be increased, or the speed of the needle selecting lever must be increased. If the number of butts on the jacks is increased, then it is necessary for the length of not only the jacks but also the needle cylinder and assocaited parts to be increased, and the number of electromagnetic devices for selecting needles must be increased. Thus, the structure of such an apparatus is very complex and the cost of manufacturing the apparatus is correspondingly high.

An object of the present invention is to provide an electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine, which overcomes the above discussed disadvantages of known apparatus.

According to the Invention there is provided an electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine, comprising a needle selecting lever pivotally mounted intermediate its ends, and having a first end for engagement with a butt of a needle selecting jack mounted on a needle cylinder, and a second end having a plurality of permanent magnets mounted in a row thereon, adjacent magnets in the row being of opposite polarity; and an electromagnetic device having a core with a pole face facing the permanent magnets on the lever, and carrying a coil by selective energisation of which the pole face can be given either polarity, the arrangement being such that in use with the pole face given one polarity the lever ip pivoted to a positiori in which the first end of the lever will engage a butt of a needle selecting jack, and with the pole face given the opposite polarity the lever is pivoted to a position in which there will be no engagement between the first end of the lever and a butt of a needle selecting jack.

The apparatus of this invention can have high efficiency with high speed and stable selection of needles due to a reduction in the operating time of the needle selecting lever with a jack lifting up method or a jack press method in a multiple jack mechanism.

Further, the apparatus of the invention is of simple structure and is easy to manufacture and to assemble.

The invention will now be described by way of example with reference to the drawings, in which: Figure 1 is a schematic plan view of a first embodiment of apparatus according to the invention using a jack lifting up method of operation; Figure 2 is a vertical longitudinal sectional view of the apparatus of Fig. 1; Figures 3 and 4 are schematic plan views of part of the apparatus of Figs. 1 and 2 illustrating the operation thereof; Figure 5 is a schematic plan view of a needle selecting lever of the apparatus of Figs. 1 to 4 showing engagement of the lever with a butt of a needle selecting jack; Figure 6 is a schematic plan view similar to Fig. 5, and showing an angle relationship between the lever and the butt of the jack; Figure 7 is a schematic plan view similar to Fig. 5, but showing the lever in a different operational position from that shown in Fig.

5; Figure 8 is a partial perspective view of a jack and a needle selecting lever of the apparatus of Fig. 1; Figure 9 is a schematic plan view of a second embodiment of apparatus according to the invention usuing a jack press method of operation; Figure 10 is a vertical longitudinal sectional view of the apparatus of Fig. 9; Figure 11 is a partial perspective view of a needle selecting jack and a needle selecting lever of the apparatus of Fig. 9; Figure 12 is a schematic plan view of a third embodiment of apparatus according to the invention using another jack press method of operation; Figure 13 is a vertical longitudinal sectional view of the apparatus of Fig. 12; Figure 14 is a perspective view of a set of needle selecting levers of the apparatus of Fig. 12; and Figure 15 is a schematic plan view of a fourth embodiment of apparatus according to the invention.

The same reference numerals are used for corresponding parts throughout the drawings.

An electromagnetic needle selecting apparatus according to the invention can be used with a multiple jack mechanism with a jack lifting up method or a jack press method of operation for use in the patterning mechanism of a circular knitting machine such as a hosiery circular knitting machine.

With regard to the apparatus shown in Fig.

1, a cylinder 1 of a circular knitting machine is rotated around an axis 0 (shown in Fig. 6) in a direction shown by an arrow head. Vertical grooves 2 for mounting needles and jacks of knitting elements are formed on an outer cylindrical wall of the cylinder 1, and each needle (not shown) and jack 3 are vertically slidably disposed in a groove 2. Since multiple jacks 3 are disposed on the cylinder 1, butts 36 project from the outer surface of the cylinder 1 at a predetermined spacing from each other.

As shown in Fig. 2, the apparatus has a base 4 carrying a plurality of needle selecting levers 8 and a base 1 8 carrying a plurality of electromagnetic devices 20 respectively associated with the levers 8. The base 4 is Lshaped, having a horizontal wall 41 fixed on a knitting machine table 5 by screws 6. Horizontal grooves 43 are provided in a vertical wall 42 of the base 4 in a vertical line, and a vertical groove 44 is provided at an outer end portion of the vertical wall 42. A hard pin 7 of small diameter which serves as a fulcrum pin for the needle selecting levers 8 is retained in the vertical groove 44 by a supporting plate 10 and screws 9.

Each needle selecting lever 8 is L-shaped, and a first end of the lever 8 is provided with an inclined portion 81 for engagement with a butt 36 of a jack 3. A small diameter hole 82 is formed at a center of each lever 8 to receive the fulcrum pin 7. Each lever 8 has a second end which is formed as an arc-shape base 83 on which are mounted three permanent magnets 15, 16, and 17.

The needle selecting levers 8 are respectively slidably inserted in the horizontal grooves 43 of the vertical wall 42 of the base 4, and the pin 7 extends through the fulcrum hole 82 in each needle selecting lever 8.

Thus, the needle selecting levers 8 can each pivot about the pin 7 relative to the base 4.

As shown in Fig. 1, a pair of stop members 11, 1 2 is mounted and fixed beside each needle selecting lever 8 on the vertical wall 42 of the base 4 by screws 13,14. There is a predetermined space between ends 111 and 121 of the stop members 11 and 12 to limit the pivotal movement of the needle selecting lever 8.

The three permanent magnets 15, 1 6 and 1 7 are fixed with a predetermined spacing to the arc-shaped second end 83 of each needle selecting lever 8 by a bonding agent such as a two-part adhesive 37 (Figs. 3 and 4) adjacent magents being of opposite polarity. In this embodiment, the permanent magnet 1 6 which has a south magnetic pole is located in the center while the other two permanent magnets 1 5 and 1 7 which have north magnetic poles are located on opposite sides of the center permanent magnet 1 6. Otherwise the center permanent magnet can have a north pole and the outer permanent magnets can have a south pole.

The permanent magnets can be of any shape, but preferably square shaped permanent magnets are used since these function best with the associated electromagnetic device 20. The spacing between the permanent magnets 15, 16 and i 7 is dependent upon the required stroke for the needle selecting lever 8, and in this embodiment the distance is 3/8 of the width of each permanent magnet.

As shown in Fig. 2, a base 1 8 carrying the electromagnetic devices 20 is mounted and fixed by screws 1 9 on a rear portion of the bottom wall 41 of the base 4. The base is of non-magnetic material and is contructed to isolate the magnetic fields of the electromagnetic devices.

In this embodiment, the base 1 8 is made from an aluminium material.

In a vertical wall 181 of the base 18 grooves 1 82 are provided in a vertical line and aligned with the permanent magnets mounted on respective ones of the needle selecting levers 8. The grooves 182 are at the same pitch as the grooves 43 in the vertical wall 42 of the base 4, which receive the needle selecting levers 8. As shown in Figs. 3 and 4, each electromagnetic device 20 comprises a yoke 21, a right coil 22, a left coil 23, a right core 24, a left core 25 and nuts 26 and 27. The number of electromagnetic devices 20 is the same as the number of needle selecting levers 8, and the yokes 21 are-fixed in respective grooves 182 by screws 28 shown in Fig. 2.

Each electromagnetic device 20 comprises a pair of parallel cores 24 and 25 on which the coils 22 and 23 are respectively wound, a stud 242 or 252 of each core 24 or 25 being fixed in a hole 211 or 212 in yoke 21 buy a nut 26 or 27. The inner ends 241 and 251 of the cores 24 and 25 are bent to extend towards each other. The faces of the ends 241 and 251 of the cores 24 and 25 provide pole faces facing the three permanent magnets 15, 16 and 1 7 mounted on the associated needle selecting lever 8.

The coils 22 and 23 are electrically connected in series through lines 29 and 30 to a patterning control apparatus which is not shown in the drawings.

An upper plate 31, shown in Figs. 1 and 2, is fixed across the top of the vertical walls 42 and 181 of the bases 4 and 18 to keep a predetermined distance between the bases.

In Fig. 1, a release lever 33 which is pivotally mounted on a fulcrum rod 34, is disposed adjacent the needle selecting levers 8 and is operable to prevent operation of the levers 8 during knitting of a garment.

Operation of the first embodiment of apparatus will now be described.

In Figs. 3 and 4, signals for patterning the knitted goods being produced are sent to the coils 22 and 23 through lines 29 and 30 from a patterning control apparatus which is not shown in the drawings.

Referring to Fig. 3, when a south pole is excited by the right coil 22 on the core 24 and a north pole is excited by the left coil 23 on the core 25, the magnetic field of the south pole (hereibafter referred to as "S") arises at the end 241 of the core 24 and the magnetic field of the north pole (hereinafter referred to as "N") arises on the end 251 of the core 25. The end 241 of "S" of the core 24 attracts the permanent magnet 1 5 of "N" which is mounted on the base 83 of the second end of the associated needle selecting lever 8, and the end 251 of "N" of the core 25 attracts the permanent magnet 16 of "S".

Moreover, the end 251 of "N" of the core 25 repels the permanent magnet 1 7 of "N".

Accordingly the needle selecting lever 8 swings suddenly in the direction shown by an arrow head, around the fulcrum pin 7. The needle selecting lever 8 hits the end 1 21 of the stop member 12, and one swinging operation of the lever 8 is completed. In this case, a closed electromagnetic circuit is formed as shown by a phantom line in Fig. 3, through the yoke 21, both core 24 of "S" and core 25 of "N", the permanent magnet 1 5 of "N", and the permanent magnet 1 6 of "S".

After completion of one swinging operation, the needle selecting lever 8 is at a stable standstill, and as shown in Fig. 5 a butt of a jack 3 is operatively engaged by the first end 81 of the needle selecting lever 8.

Referring to Fig. 4, the poles of the cores are oppositely excited as compared with that shown in Fig. 3. When a south pole is excited on the left coil 23 and a north pole is excited on the coil 22, the magnetic field of the south pole arises on the end 251 of the core 25 and the magnetic field of the north pole arises on the end 241 of the core 24. Accordingly, the end 251 of "S" of the core 25 attracts the permanent magnet 1 7 of "N", the end 241 of "N" of the core 24 attracts the permanent magnet 16 of "S", and the end 241 of "N" of the core 24 repels the permanent magnet 1 5 or "N".Therefore the needle selecting lever 8 swings suddenly in the direction shown by an arrow head in Fig. 4 about the fulcrum pin 7, and the needle selecting lever 8 hits against the end 111 of the stop member 11, and one reverse swinging operation is completed. In this case, a closed electromagnetic circuit is formed as shown by a phantom line in Fig. 4, through the yoke 21, both core 25 of "S" and core 24 of "N", the permanent magnet 17 of "N" and the permanent magnet 16 of "S". After completion of the reverse swinging operation, the needle selecting lever 8 is at a stable standstill, and as shown in Fig. 7, the first end 81 of the needle selecting lever 8 does not engage and operate a butt 36 of a jack 3.

As shown in Fig. 6, the fulcrum pin 7 for each needle selecting lever 8 is arranged at a predetermined angle in relation to first contact between the first end of the lever 8 and a butt 36 of a jack 3 and a tangent to the cylinder 1 at the point of contact.

When a needle selecting lever 8 is moved by operation of the associated electromagnetic device 20 in the direction shown by arrow B, and approaches the surface of the cylinder 1, there is a possibility that the lever 8 may be caused to rebound by the shock of collision with a butt 36 of a jack 3.

In Fig. 6, the needle selecting lever 8 has a front face at the first end 81 thereof, which initially contacts the butt 36 of the jack 3 parallel to the butt of the jack, that is the front face of the first end 81 of the lever 8 is parallel to a radial line O-Y from the center 0 of the cylinder and which passes through the butt 26 at y, with the fulcrum point 82 of the lever 8 positioned on a line y-R which is at a predetermined angle a to the tangent y-x to the cylinder 1 at y. Thus, when the needle selecting lever 8 engages the butt 36 of the jack 3, the lever 8 is at a certain stable position against the butt 36, and will not rebound from the impact.Thus, the speed of selection is increased, and the needle selecting lever 8 is held not only by the permanent magnets 15, 1 6 , 1 7 but also stabilised by the described positioning of the fulcrum point 82 of the lever 8.

Referring now to Figs. 9 to 11, in the apparatus have shown the first end 81 of each needle selecting lever 8 is flat as shown in Fig. 11. This different shape will be best understood from a comparison of Figs. 8 and 11. The swinging operation of each needle selecting lever 8 is the same as in the appara tus of Figs. 1 to 8. When the first end 81 of the lever 8 engages and pushes a butt 36 of a jack 3, the jack 3 rides on a cam 35 which is mounted on the knitting machine, and the jack rises.

Referring now to Figs. 1 2 to 14, in the apparatus have shown a hub 38 is provided at the center and on an under surface of each needle selecting lever 8, by which the lever 8 is pivotally mounted between vertical walls of a base 4 on a pin 39, the lever 8 thus being capable of pivotal movement about the pin 39 in a vertical plane.

A first end 81 of each lever 8 is flat and arranged to engage a butt 36 of a jack 3, and a base 83 of the second end of the lever 8 is vertically mounted and carries the permanent magnets 15, 1 6 and 1 7 in a vertical arrangement.

The needle selecting levers 8 are arranged in sets of three the levers of each set being arranged vertically with the permanent 15, 16, 1 7 thereon lying in spaced parallel vertical planes, as shown in Fig. 14.

In this apparatus, when the first end 81 of a lever 8 is swung upwardly, a butt 36 of a jack 3 is pressed along a sloping surface of the first end 81 of the lever 8.

Referring now to Fig. 15, the apparatus here shown is substantially the same as that shown in Figs. 1 to 8 the essential differences being that it includes a different form of stop means which now comprises a relatively large diameter hole 45 formed in each needle selecting lever 8 and a relatively small diameter pin 46 which projects from the base 4 and engages with clearance in the hole 45 thereby to permit only limited pivotal movement of the lever 8 about the fulcrum pin 7.

Further, the release lever 33 for the needle selecting levers 8 is arranged to contact and push a projecting portion 47 on each needle selecting lever 8 to remove the lever to a nonoperational position.

With regard to operating time, a conventional needle selecting apparatus can operate in about 9 to 10 milliseconds, with the rotation of the needle cylinder being limited to about 220 to 230 r.p.m., in an apparatus in which 240 needles are set and a set of jacks includes 1 6 jacks. With all the embodiments of apparatus according to the invention described above the operating time of the needle selecting apparatus is about 4.5 to 5 milliseconds, and the rotation of the needle cylinder can be increased to more than 400 r.p.m.

when there are 240 needles and a set of jacks includes 1 6 jacks.

Claims

1. An electromagnetic needle selecting apparatus for use in the patterning mechanism of a circular knitting machine, comprising a needle selecting lever pivotally mounted intermediate its ends, and having a first end for engagement with a butt of a needle selecting jack mounted on a needle cylinder, and a second end having a plurality of permanent magnets mounted in a row thereon, adjacent magnets in the row being of opposite polarity; and an electromagnetic device having a core with a pole face facing the permanent magnets on the lever, and carrying a coil by selective energisation of which the pole face can be given either polarity, the arrangement being such that in use with the pole face given one polarity the lever is pivoted to a position in which the first end of the lever will engage a butt of a needle selecting jack, and with the pole face given the opposite polarity the lever is pivoted to a position in which there will be no engagement between the first end of the lever and a butt of a needle selecting jack.

2. An apparatus as claimed in claim 1, in which there are three permanent magnets mounted on the second end of the lever.

3. An apparatus as claimed in claim 1 or claim 2 in which the electromagnetic device has two cores each with a pole face facing the permanent magnets.

4. An apparatus as claimed in any preceding claim, in which a portion at the first end of the lever is bent out of the plane of the remainder of the lever for engagement with a butt of a needle selecting jack.

5. An apparatus as claimed in claim 1, claim 2 or claim 3, in which the first end of the lever has an inclined surface arranged for lifting a needle selecting jack by engagement with a butt thereof.

6. An apparatus as claimed in claim 1, claim 2 or claim 3, in which the first end of the lever is arranged to press in the plane of the lever against a butt of a needle selecting jack.

7. An apparatus as claimed in any one of claims 1 to 4, in which the first end of the lever is arranged to make initial contact with a butt of a needle selecting jack parallel to the butt, the line between the point of contact between the first end of the lever and the butt being at a certain angle to the tangent to the needle cylinder at said point whereby the first end of the lever is maintained in contact with the butt after initial contact therewith.

8. An apparatus as claimed in any preceding claim, including a release lever operable to prevent operation of the needle selecting lever when required.

9. An apparatus as claimed in any preceding claim, including stop means arranged to limit the movement of the needle selecting lever.

10. An apparatus as claimed in claim 9, in which the stop means comprises two stop members engaged by the needle selecting lever when positioned in its two said positions respectively.

11. An apparatus as claimed in claim 9, in which the stop means comprises an independently mounted pin freely received in a hole in the needle selecting lever.

12. An apparatus as claimed in any preceding claim, including a plurality of said needle selecting levers and associated electromagnetic devices.

1 3. An electromagnetic needle selecting apparatus substantially as hereinbefore described with reference to, and as shown in, Figs. 1 to 8, Figs. 9 to 11, Figs. 1 2 to 14, or Fig. 1 5 of the drawings.