US3810368A

US3810368A - Patterning mechanisms for knitting machines

Info

Publication number: US3810368A
Application number: US00145824A
Authority: US
Inventors: T Wade; I Fleckney; S Savage
Original assignee: Wildt Mellor Bromley Ltd
Current assignee: Wildt Mellor Bromley Ltd
Priority date: 1970-05-22
Filing date: 1971-05-21
Publication date: 1974-05-14
Anticipated expiration: 1991-05-14
Also published as: FR2093555A6; GB1344078A; IT989589B; JPS5242901B1; DE2125238A1

Abstract

A patterning mechanism for a knitting machine comprising a bank of selector elements each associated with individual electromagnetic means for movement between selection and non-selection positions, in which means is provided to constrain the magnetic flux produced by the electro-magnetic means to follow a predetermined magnetic path whereby the influence of any electromagnetic means upon any selector other than the associated selector is reduced to negligible proportions.

Description

United States Patent [191 Wade et a1.

[ PATTERNING MECHANISMS FOR KNITTING MACHINES Inventors: Thomas Cyril James Wade, Harcourt; 1an Matthewson, Fleckney; Sidney Clifford Savage, Wigston Magna, all of England Wildt Mellor Broimley Limited, Leicester, England Filed: May 21, 1971 Appl. No.: 145,824

Assignee:

Foreign Application Priority Data May 22-, 1970 Great Britain 25043/70 us. Cl ..-....'66/5 0 R rm. Cl D04b 15/78 Field of Search. 66/50 R, 50 B, 25, 75,

References Cited UNITED STATES PATENTS 3,492,836 2/1970 Blood et a1. 66/155 X [ll] 3,810,368 [451 May 14, 1974 1,560,778 11/1925 Goddard 200/166 L 3,550,398 12/1970 Widdowson 66/50 R 2,439,126 4/1948 Buttrey 200/166 L Primary Examiner-Wm. Carter Reynolds fl .9f izu aq amei fymiwsiqm tlias le were Weintraub 7 A patterning mechanism for a knitting machine comprising a bank of selector elements each associated with individual electro-magnetic means for movement between selection and non-selection positions, in which means is provided to constrain the magnetic flux produced by the electro-magnetic means to follow a predetermined magnetic path whereby the influence of any electro-magnetic means upon any selector other than the associated selector is reduced to negligible proportions.

- ABSTRACT 4 Claims 2 Drawing Figures "III 5 'illllll G dimmin- I I i p /||||||II|| g Q) 3' 10b PATENTEHMAY 141974 SHEET 2 OF 2 lOb IOb

ll-lul IHHM i lll flww D i FIGZ PATTERNING MECHANISMS FOR KNITTING MACHINES This invention relates to electromagnetically operated patterning mechanism for' knitting machines. It has particular reference to such mechanisms of the type described in U.S. Pat. No. 3,550,398 and is an improvement in or modification of the invention described and claimed in that patent.

It will be appreciated that, in applying electronic and ,electro-magnetic devices to control the patterning mechanism of knitting machines, various limitations are imposed on the design of the controlling devices particularly when they form an integral part of the patterning mechanism. For instance, if the actual selection of the needles is obtained in conventional .fashion e.g. by a bank of selectors located close to a needle cylinder and acting directly upon butts associated with the needles, then the electro-magnetic devices for controlling the bank of selectors must be confined in a small space unless considerable re-design of the knitting machine is carried out.

In the case of patterning mechanism in which each selector of the aforementioned bank is controlled by an electro-magnetic coil it follows that a number of electro-magnetic coils will be situated in close proximity to one another and this'can give rise to faulty actuation of the selector levers due to the magnetic fields of the different coils causing unwanted interference with one another. The actual effect of the interference is such that, when an electric pulse is produced in a particular coil in order to-obtain an effect upon its associated selector lever, then, should other coils in the assembly also be pulsed substantially simultaneously, the magnetic field created by the other coils may cause the selector lever associated with the particular coil to malfunction to such an extent that the selector lever is not operated in the desired manner.

An object of the presentinvention is to provide, in association with patterning mechanism of. a knitting machine, an assembly of closely situated magnetic coils each controlling a selector and which are capable of being energised in any particular sequence, or in'any number simultaneously, without causing malfunction of the selectors. It is naturally economically desirable for this to be achieved in as simple and inexpensive a manner as possible.

According to the invention there is provided a patterning mechanism for a knitting machine in which means is provided to'constrain the magnetic flux produced by the electromagnetic means to follow a predetermined individual magnetic'path whereby the influence of any electro-magnetic means upon any selector other than the associated selectoris reduced to negligible proportions.

The constraining means is preferably in the form of material of very high permeability.

More specifically, in the case where each electromagnetic means comprises a permanent magnet and a single coil, there is provided in association with each of g the coils a shelf in the form of a strip or bar of magnetic material and which is disposed in such a way that the magnetic flux produced by the associated coil when energised is guided or folded in a more constrained path by virtue of its passage through the strip or bar. In this way, not only is interference with adjacent coils minimized, but also leakage of the magnetic flux is minimized. 7

When putting the invention into practice the strip or bar, which may be made of soft iron, can be arranged in the form of a shelf or support for the coil and magnet associated with it, the shelves and coils combining to form part of a compact unit which includes the bank of selector elements.

Whilst the invention is applicable to most types of knitting machine, both flat and circular, it will now be described in detail with reference to the accompanying drawings as applied to a circular machine of the revolving cylinder type equipped with patterning mechanism of the type described in the US. Pat. No. 3,550,398. It will be appreciated that in showing the invention as applied to this particular patterning mechanism it is not limited to such an arrangement and may be used in all cases where the close spacing of electro-magnetic coils is desirable.

In the drawings:

FIG. 1 is a sectional side view through part of the needle cylinder and associated parts of the knitting'machine, showing the knitting instruments and a patterning unit; and

FIG. 2 is a perspective view of some of shown in FIG. 1.

In FIG. 1 a rotary needle cylinder 1 is shown provided with tricks 2 which house needles 3. Also provided in the tricksare spring jacks 4 and rocking pressers 5 the arrangement being that the needles 3 and spring jacks 4 are vertically displaceable in the cylinder tricks 2 while the pressers 5 are restrained from vertical movement by their engagement with a fulcrum ring 6 about which they may be rocked.

Rocking of a presser 5 in the anti-clockwise direction as viewed in FIG. 1 causes depression of a pattern butt 4a of the spring jack into its trick 2 so that it passes behind a raising cam 7 and is not raised thereby.

Thepressers are rocked outwardly at their upper end by a cam 8 acting on them seriatim as the needle cylinder revolves. This action brings the upper ends of the rockers into the influence of a permanent magnet 9 which retains the rockers after they pass beyond the cam 8. The butt 4a is then depressed into the-trick 2. It is only necessary to push selected pressers 5 off the magnet 9 in order to allow the depressed butts 4a of the jacks 4 to spring out and engage the raising cam 7 for subsequent operation of the needles.

To carryout this selective pushing of pressers 5 off the magnet, a bank of selectors, shown generally at 10 the parts in FIG. 1, is arranged in a unit 11 adjacent the needle cylinder 1 and the rocking pressers 5. Each presser 5 is provided with a butt 5a and the butts of consecutive pressers are arranged in selected spaced horizontal planes equal in number to the number of selectors 10 in the bank. In their inactive position the selectors 10 have their operating camming ends 1012 in planes between the planes of the butts 5a which planes are sufficiently spaced apart vertically to allow the butts 5a to miss the selector ends 1012 when they are in the inactive position. Movement of a selector to active position causes its end 10b to lie in a plane of a butt 5a so that the camming edge will push on the butt 5a and disengage the upper end of the presser 5 from the magnet 9.

Each selector is in the form of a first order lever with one arm carrying the end 10b and the other arm 10a made of soft iron, passing through an associated electro-magnetic coil. The movement of the selectors from an operative position to a non-operative position and vice versa, is brought about by the series of electromagnetic coils 12 (see FIG. 2) through which the soft iron arms 10a of the selectors 10 pass, with an extreme end 100 of each selector locating in between the two poles of a permanent magnet 13.

When the electro-magnet coil 12 associated with a particular selector 10 is energized it causes the arm 10a of the selector to become magnetized and, depending upon the polarity of the energization, the polarity of the selector arm 10a will be north or south. It will therefore be attracted to one of the two poles of the permanent magnet 13 and repelled from the other. By pulsing the coil in opposite polarities according to a predetermined sequence, the selector can be moved between operative and inoperative positions as desired.

Because patterning mechanism of this type must be operated at extremely high speeds, it will be appreciated that the coils associated with a bank of selector levers must be pulsed at a very rapid rate (e.g. more than 100- times per second) and any oneselector arm 100 may be attracted to one pole of the permanent magnet 13 and almost immediately repelled therefrom by a change of polarity and attracted to the opposite pole. It is natural that a certain amount of bounce can take place as the selector end 10c strikes the pole face of the magnet 13 and it can be appreciated that, unless the mutual attraction of the selector end 10c and the particular pole face of the magnet 13 is strong, there is a possibility that the selector will not adhere properly to the selected pole face. This strong mutual attraction can be impaired if the magnetization of the selector'end 10c is not efficiently achieved. Should the pattern of electric pulses in the closely situated coils be such that a strong magnetic flux of one polarity is created then a selector may well be influenced in mid-bounce to be attracted to the wrong pole face.

in the specific arrangement under discussion, in accordance with the invention, there is associated with each selector arm 10a and its associated coil 12 and permanent magnet 13, a strip 14 of soft iron which is arranged in such a position that the magnetic flux created by the coil is constrained to follow a magnetic circuit around the arm 10a, coil 12 and the appropriate pole of the magnet 13. Loss of magnetization in the selector arm 10a is therefore reduced to a minimum and the magnetic flux generated by the coil 12 is substantially prevented from affecting adjacent selectors.

Depending upon different conditions determining the size, configuration and location of the selectors, coils and magnets, various arrangements of the strips 14 may be decided upon, and the example shown in FIG. 2 is one in which the strips are in two vertical rows and staggered relatively to one another. The strips 14 have also been adapted to form shelf-like supports for the associated coils and magnets, the shelves being slotted into side walls 11 of the selector unit.

Various modifications may be made within the scope of the invention.

We claim:

1. In a patterning mechanism for a knitting machine of the type comprising a bank of selector elements each associated with individual electro-magnetic means for movement between selection and non-selection positions and wherein each of the electro-magnetic means comprises a permanent magnet and a single coil, the improvementwhich comprises: a separate shelf of high magnetic permeability for each of the electro-magnetic means to constrain the magnetic flux produced by the individual electro-magnetic means to follow predetermined individual magnetic flux paths whereby the influence of any of the electro-magnetic means upon any selector element other than the selector element associated therewith is reduced to negligible proportions, said shelf supporting the magnet and coil associated therewith.

2. A patterning mechanism as claimed in claim 1, in which the shelf is soft iron.

3. A patterning mechanism as claimed in claim 1 in which each shelf is in the form of a strip or bar and which is disposed in such a way that the magnetic flux produced by the associated coil when energised is guided in a more constrained path by virtue of its passage through the shelf.

4. A patterning mechanism as claimed in claim 1, comprising a compact patterning unit into which all of the shelves and coils are assembled, with the bank of selector elements.

Claims

1. In a patterning mechanism for a knitting machine of the type comprising a bank of selector elements each associated with individual electro-magnetic means for movement between selection and non-selection positions and wherein each of the electromagnetic means comprises a permanent magnet and a single coil, the improvement which comprises: a separate shelf of high magnetic permeability for each of the electro-magnetic means to constrain the magnetic flux produced by the individual electromagnetic means to follow predetermined individual magnetic flux paths whereby the influence of any of the electro-magnetic means upon any selector element other than the selector element associated therewith is reduced to negligible proportions, said shelf supporting the magnet and coil associated therewith.