GB2204601A

GB2204601A - Method of magnetically selecting knitting machine instruments

Info

Publication number: GB2204601A
Application number: GB08810116A
Authority: GB
Inventors: Shinji Kawase; Toshiro Izumi
Original assignee: Precision Fukuhara Works Ltd
Current assignee: Precision Fukuhara Works Ltd
Priority date: 1987-05-06
Filing date: 1988-04-28
Publication date: 1988-11-16
Also published as: GB8810116D0; IT1219930B; JPH043030Y2; DE3814883A1; JPS63177979U; IT8847902A0; IT1219931B; IT8847901A0

Description

1 2 2 0 1 6l, 1 METHOD OF MAGNETICALLY SELECTING KNITTING MACHINE PAFTS

This invention relates generally to a method of magnetically selecting metallic knitting machine instrumentalities, such as knitting needles, sinkers, selector jacks, and the like, which include selector butts normally being of the same thickness as the main body of the knitting machine iinstrumentalities, and more particularly to such a method which includes the step of increasing the thickness and metallic mass of the selector butt to thereby facilitate the exertion of the magnetic selecting force thereon.

It is known to provide magnetic needle selection in circular knitting machines by providing butt portions on various knitting instrumentalities, such as knitting needles, sinkers, selector jacks and the like, and to subject the selector butts to the action of a magnetic selecting force field by means of selectively operable electromagnetic selectors supported in spacer:apart positions around the knitting machine. The electromagnetic selectors are selectively operable to produce a magnetic force field through which the selector butt portions of the knitting machine instrumen-

4 talities pass in the process of forming knit fabric. It is the normal practice to stamp or punch the knitting machine instrumentalities out of steel plate material so that the thickness of the selector butt portions is the same as the thickness of the remaining parts of the knitting machine instrumentalities. Because the knitting instrumentalities are normally punched out of a very thin steel plate, the selector butt portions have a very small metallic mass and the capacity of the selector butt portion for being attracted by a magnetic force field is very limited. Magnetic saturation of the very thin selector butt portions can easily occur, and this makes it impossible to increase the magnetic force to an amount which is sufficient to attract the selector butt portion.

It is an object of the present invention to provide a method of magnetically selecting metallic knitting machine instrumentalities, such as knitting needles, sinkers, selector jacks and the like, by increasing the thickness and metallic mass of the selector butts of the knitting machine instrumentalities and to thereby facilitate the exertion of a magnetic force field thereon when the selector butt portion passes through the magnetic force field.

In accordance with the present inve-ntion, the metallic mass of the selector butt portion is increased by affixing at least one reinforcing member, in the form of a metallic plate member, to at least one side of the selector butt portion of the knitting machine instrumen- tality. The metallic plate member may be mounted on only one face of the selector butt portion of the knitting machine instrumentality,-or t4e metiallic plate member may be mounted on both faces of the selector butt portion.

1 The thickness of the metallic plate member will vary, according to the diameter and t,- gauge (number of needles per inch) of the knitting machine cylinder. When the metallic plate member is mounted on only one face of the selector butt portion, the thickness will be a little less than the dimension which results from subtracting the needle thickness dimension from the dimension from one space of the cylinder grooves to the next. When the metallic plate member is mounted on both faces of the'selector butt portion, its thickness should be approximately one-half of the thickness of the metallic plate member mounted on only one face. The width of the metallic plate member in a projecting direction of the selector butt is not particularly limited except that it should be less than the height of the butt projecting from the stem. While the metallic plate member is described as being steel, it is to be understood that this me ' tallic plate me.mber may be formed of other types of material which will be attracted by a magnetic force field. The metallic plate member may be attached to or mounted on the selector butt portion of the knitting machine instrumentality in any suitable manner and welding is preferred. Either laser or master welding with two or four spot welds is also preferred.

The inventon will now be described' by way of example with reference to the accompanying partly diagrammatic drawings, in which:- Figure 1 is a perspective view of a selector jack with a plate member fixed to one face of the selec- tor butt portion, in accordance with one embodiment of the present invention; Figure 2 is a greatly enarged fragmentary sec- 2 tional plan view illustrating a portion of the needle cylinder and showing plate members fixed on one face of the selecting butts of adjacent selector jacks mounted for vertical sliding movement in the needle cylinder grooves; Figure 3 is a view similar to Figure 2 but illustrating the plate members fixed on both faces of the selector butts of the selector jacks; Figure 4 is a perspective view of a sinker and illustrating another embodiment of the invention with a plate member fixed on the selecting butt of the sinker; and Figure 5 is a perspective view of a knitting needle with a plate member being fixed on one side of the outwardly projecting selector butt on the lower portion thereof, in accordance with another embodiment of the present invention.

In the first embodiment of the invention shown in Figure 1, a selector jack, broadly indicated at 10, is illustrated. The selector jack 10 is of a conventional type normally u.-ed in a circular knitting machine and includes an elongated stem portion 13 having an upper end portion 11 adapted to contact the lower end of a knitting needle, not shown. A rocking free end 12 is provided at the lower end of the jack 10 and an inwardly projecting rocking pivot portion 14 is provided in the 25- medial portion of the jack 10. An outwardly projecting operating butt 15 is positioned opposite the rocking pivot portion 14 and is adapted to engage conventional operating cams, not shown, provided in the knitting machine for imparting longitudinal movement to the selector jack 10 in a conventional manner. An outwardly extending selector butt 17 is positioned below the operating butt 15 and is adapted to pass through a magnetic force field selectively produced by an electromagnetic selector 16. In order to facilitate the exer- h t tion of the magnetic -force field on the selector butt 17, a reinforcing member, in the form of a metallic plate member 18, is affixed to one side of the selector butt 17, as shown in Figures 1 and 2. The metallic plate member 18 may also be affixed to both faces of the butt portion 17, as illustrated in Figure 3.

The thickness of the metallic plate member 18 will vary according to the diameter and the gauge (number of needles per inch) of the knitting machine cylinder C. When a plate member 18 is attached to only one face of the selector butt portion 17, as shown in Figures 1 and 2, the preferred thickness is dimension T2 which is slightly less than the dimension Tl which is obtained by subtracting the needle thickness dimension t from one groove space P of the needle cylinder C. For example, in a circular knitting machine having a 30 inch diameter cylinder and 28 gauge, the thickness of the selector jack is 0.42 and the thickness of the plate 18 is also 0.42 mm.

When the plate member 18 is attached to both -t portion 17, as shown in faces of the selector but Figure 3, the thickness of the plate member 18 should be approximately one-half of the thickness of the plate member when placed on only one side of the selector butt 17, as illustrated in Figure 3. The width of the plate member 18 is not critical but should be less than the outwardly projecting length of the selector butt 17. The material of which the plate member is formed must be some type of magnetically attractable substance and is preferably steel. The plate member 18 is illustrated in Figure 1 as being attached to the selector butt 17 by laser welding at two spaced-apart spots.

In Figure 4, the present invention is shown as being embodied in a sinker, broadly indicated at 20, which is of the conventional type normally used in a circular knitting machine. The sinker 20 includes a stitch forming ledge portion 22 at its forward end with a nose or neb 21. The rear portion 24 of the sinker 20 has an upstanding selector butt 23. The forward stitch forming ledge portion 22 is connected to the rear portion 24 by an intermediate bridging portion 25. In accordance with the present invention, a metallic plate 26 is attached to one side of the butt 23 to increase the thickness and metallic mass of the metallic selector butt 23 and to thereby facilitate the exertion of the magnetic force field thereon when the thickened selector butt portion (23 and 26) passes through the magnetic force field selectively generated by the electromagnetic selector device 16.

Figure 5 illustrates a third embodiment of the invention as applied to a latch needle, broadly indi cated at 30. The latch needle 30 is of a conventional type used in a circular knitting machine and is provided with an elongate upper stem portion 32 having a hook 31 at the upper end. A latch 34 is pivoted for movement between open and closed positions with the hook 31 for forming stitch loops in a conventional manner. A lower stem prtion 35 is resiliently connected to the upper stem portion 32 and an upper operating butt 36 extends outwardly from the lower end of the upper stem portion 32 while a lower actuating butt 37 extends outwardly from the lower end of the lower stem portion 35. An intermediate selector butt 38 extends outwardly from the medial portion of the lower stem portion 35 of the needle and is provided with a metallic plate member 39 fixed to one side thereof. The plate member 39 increases the thickness and metallic mass of the metallic selector butt portion (38 and'39) to thereby facilitate the exertion of the magnetic force field thereon when the thickened selector butt portion passes 1 1 1 through the magnetic force field created by the selectively operable electromagnetic selector 16.

The effect of the present invention was tested by comparing the attractive force of a magnet exerted on five jacks 10 provided with the metallic plate member 18 of the present invention (product of the first embodiment of the invention) with the attractive force exerted on five conventional jacks (product having the same construction with the first embodiment except without a plate member attached to the butt portion). The attractive force was measured in terms of current value, while the gar) between the magnet and each of the jacks was varied. When the gap between the magnet and the jacks was 0.06 mm, the mean measured attractive force value of the five conventional jacks was 0.53A while the mean measdred attractive force value was 0.98A with jacks having thickened butts in accordance with the present invention. When the gap was 0.12 mm, the conventional jacks did not measure-a: current value, but the jacks of the present invention,&jith the thickened butts produced a value of 0.88A. This result clearly indicates that the product of this invention provides almost twice as much facility in exertion of magnetic force as the,conventional jacks. Because the permissible margin for the gap between the jack and the magnet is thus increased, the adjustment at the time of assembly is simplified.

In the drawings and specification there has been set forth the best mode presently contemplated for the practice of the present invention, and although spe- cific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

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Claims

CLAIMS 1 1. In a method of magnetically selecting metallic knitting machine instrumentalities, such as knitting needles, sinkers, selector jacks, and the like, in a circular knitting machine including electromagnetic selectors supported in spaced-apart positions around the knitting machine and being selectively operable to produce a magnetic force field through which the selector butt portions of the knitting machine instrumentalities pass in the process of forming knit fabric, and wherein the selector-butt portions are normally of the same thickness as the main body of the knitting machine instrumentalities, the improvement thereof comprising the step of increasing the thickness of the metallic selector butt portion of the knitting machine instrumen- talities to increase the metallic mass thereof and to thereby facilitate the exertion of the magnetic force field thereon when the thickened selector butt portion passes through the magnetic force field.

1

2. In a method according to Claim 1 wherein the metallic mass of the selector butt portion of the knitting machine rnstrumentality is increased by affixing a metallic plate member to one side of the selector butt portion of the knitting machine instrumentality.

3. In a method according to Claim 2 wherein said plate member is affixed to said selector butt por tion by spot welding.

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4. In a method according to Claim 2 wherein the thickness of saild plate member is substantially the same as the thickness of said selector butt portion to which it is affixed.

5. In a method according to Claim 1 wherein the metallic mass of the selector butt portion of the knitting machine instrumentality is increased by affixing a metallic plate member to each side of the selector butt portion of the knitting machine instrumen- tality.

6. A method of magnetically selecting metallic knitting machine instrumental ities substantially as hereinbefore described w-4th reference to the accompanying drawings.

A Published 1988 at The Patent Office, State House, 66,171 High Holborn, London WC1R 4TP. Further copies may be obtained from The Patent OfncL, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1187, 1