GB2188335A - Needle selection mechanism for circular knitting machine - Google Patents

Abstract

A selection mechanism for a circular knitting machine includes a plurality of selector levers 60 mounted pivotally in elongated grooves 31 provided one above the other at one side of a selector block 30. The selector levers are turnable about a vertical axis and actuated by a plurality of horizontal solenoid-operated arms 50 which are connected to them respectively. A variety of patterns can be produced using the selection mechanism. The levers 60 and grooves 31 may be horizontal as shown in which case the levers are actuated to render needles inoperative or the may be inclined and the levers move needles to an operative position. <IMAGE>

Description

SPECIFICATION Needle selection mechanism for circular knitting machine This invention relates to a needle selection mechanism for a circular knitting machine, and particularly to a needle selection mechanism having solenoid operated selector means for selecting and controlling needles of the knitting machine.

Atypical circular weft knitting machine is shown in Figure 1, which, generally, includes a machine body 10,a lower disc 11,a middle disc 12, an upperdisc 13, a needle cylinder 14, a selector cylinder 15, a yarn support means 16, a yarn feeding means 17 on the upper disc 13, etc., wherein the needle cylinder 14 is disposed on the middle disc 12 and extends upward through the upper disc 13. Referring to Figures 1 - 6, on the periphery of the needle cylinder 14 are regularly spaced apart needle grooves 18 each receiving a needle 19, a movable long needle plate 20 and a movable short needle plate 21. Adjacent to the lower portion of the periphery of the needle cyclinder 14are annularly disposed lifting cam pieces 22.

When the needle cylinder is rotated, the butt 201 of each long needle plate 20 is cammed by the cam pieces 22 so that the hook 191 of the respective needle 19 is lifted to the yarn feeding station 171 of the yarn feeding means 17 to proceed with the stitching operation. The pattern ofthe resultant knitted fabric depends upon a mechanism which governs the lifting of the needles.

There are many kinds of mechanisms forselecting and controlling the needles. The mechanism shown in Figures 2 to 6 is a typical one, wherein the needles 19 are lifted by using selector plates 23 which are actuated by the selector cylinders 15. The selector plates 23 are mounted forturning about a shaft 232 neartheneedlecylinderl4. lntheperipheryofthe cylinder 15 are provided longitudinal grooves 151 receiving selector rack 24 in a fixed position.

As shown in Figure 7, the selector cylinder 15 may have any number and shape of selector plates 24 as desired. When the selector plate 23 is pushed towards the needle cylinder by the tooth 241 of the selector rack 24, the plate 23 in turn pushes the butt 211 of the respective needle plate 21 so that the needle plates 20 and 21 are depressed in the needle groove and the butt 201 of the needle plate 20 is released from the lifting cam piece 22. In this situation, the needle 19 is in an inoperative position.

As shown in Figures3 and 5 and Figures4and 6, when the selector plate 23 does not contact the tooth 241 of the selector rack 24, the butt 201 ofthe needle plate 20 will be cammed by the lifting cam piece 22 and the needle 19 will be lifted to the stitching position.

An alternative way to select the needle 19 is a method wherein the needle 19 is not lifted by means of a lifting cam piece but with a selector plate 23 which is modified to have a slant configuration to engage with and disengage from the short needle plate 21. In this case, the needle is lifted when the selector plate 23 is calmed by the selector rack 24.

In the above-described needle selection mechanism, the selector cylinder is rotated in cooperation with the needle cylinder: when the needle cylinder 14 makes one revolution, the selector cylinder is displaced a distance ofthatfrom one selector rackto an adjacent selector rack. The pattern formed in the resultant fabric contains repeated units depending upon the diameter of the selector cylinder.

Therefore, the pattern formed not only depends upon the time required by the solenoid-operated selector rackto actuate the selector plate, but also upon the diameter of the selector cylinder.

It is an object of the invention to provide a needle selection mechanism bywhich a wide variety of patterns can be made in a fabric without influences from the conventional selector cylinder. Moreover, the mechanism can be coordinated with a computer control system to produce a variety of patterns.

The present invention provides a needle selection mechanism which comprises: a selectorblock having at one side a plurality of elongated grooves spaced apart one above the other and extending horizontally; a plurality of selector levers received in the grooves respectively and mounted pivotally in the selector blockforturning about a vertical axis; solenoid-operated arms arranged one above the other and connected to the ends of the selector levers respectively to actuate selectively the selector levers so as to put the needles in their operative positions or their inoperative positions; and a supportfor supporting the solenoid-operated arms.

The selector levers can be arranged in such a manner that they lie in different horizontal planes orthatthey are slanted relative to the horizontal planes.

In one aspect of the invention, the support includes a support plate and a plurality of solenoid casings secured to the support plate one above the other.

Each of the solenoid-operated arms has forked head extending out of the casing and pivoted respectively to one end of each of the selector levers, a stem portion mounted movably in the casing, and a solenoid coil provided around the stem portion.

The exemplary preferred embodiment will be described in detail with reference to the following drawings.

Figure lisa perspective view of a conventional circular knitting machine; Figure 2 is a schematic plan view showing the selector cylinder, the selector plate, and the needle cylinder of a conventional circular knitting machine; Figure 3is a sectional view showing the selector cylinder, the selector plate and a portion ofthe needle cylinder, wherein the needle is in an inoperative position; Figure 4 is a sectional view substantially similar to Figure 3, wherein the needle is in an operative position; Figure5is an exploded view showing a portion of the selector cylinder, the selector plate, a needle and a needle plate means, wherein the needle is in an inoperative position; Figure 6is an exploded view similar to Figure 5, wherein the needle is in an operative position;; Figure 7is an exploded view a selection mechanism according to the present invention; FigureS is a perspective view of the selection mechanism of Figure 7; and Figure 9 is a perspective view of an alternative selection mechanism.

Referring to Figures 7,8 and 9, an embodiment of the selection mechanism includes a selector block 30 having atone side elongated grooves31 spaced apart one above the other and extending horizontally. Each groove 31 is confined bytwo adjacent tongues 32. Selector levers 60a and 60b are inserted alternatively in the grooves 31 and pivoted to the selector block 30 through a pivot shaft 70 which passes through throughholes 321 provided in the tongues 32 of the selector block and holes 61 provided in the selector levers 60a and 60b. The selector levers 60b are straight plate levers and the selectorlegers 60a are L-shaped plate levers.

There are two supports 40a and 40b mounted near the selector block 30 for holding solenoid-operated arms 50. Each solenoid-operated arm 50 is mounted in one of solenoid casings 51 which is arranged one abovethe other and secured to the supports 40a and 40b by means of screws 56. Each solenoid-operated arm 50 has a forked head 55 extending out of the solenoid casing 51 and pivoted to one end of each selectorlever60a or60b, a stem 52 mounted in the solenoid casing 51, a spring 54 sleeved around the neck of the stem 52 and a solenoid coil 53 provided around the stem 52 ofthe arm 50. The solenoid-operated arms 50 mounted on the support 40a are connected to the selector levers 60a and the arms 50 mounted on thesupport40b areconnected to the selector levers 60b.When a current flows in a solenoid coil 53, the forked head 55 of the respective solenoid-operated arm 50 moves forward against the biasing action ofthespring 54 and actuates the respective selector lever 60a or 60b to move forward.

The forwardly moving selector lever 60a or 60b will in turn move a conventional needle plate, which is described hereinabove, so that the needle plate is released from the lifting cam piece and the needle is put in an inoperative position.

It can be noted that, the solenoid-operated arms are arranged into two groups which are separately mounted on two supports because the selector levers 60a and 60b are arranged very near each other. Ifthe spacing between the selector levers is sufficient to allow the forked heads 55 to be spaced apart, and the dimension of the forked heads is reduced, the solenoid-operated arms can be arranged on a single support.

Figure 9 shows an alternative selection mechanism which is of substantiallythe same construction as the former selection mechanism.

The only difference between the latter and the former mechanisms is that selector levers 60 mounted in the selector block 30 are arranged in a slanted configuration. In this case, each slanted selector lever 60 causes a needle to move to an operative position when it is actuated by the solenoid-operated arm 50, whereas, each selector lever 60a or 60b of the former selection mechanism puts a needle in an inoperative position when it is actuated by the solenoid-operated arm 50. It is to be noted that, in order to lift a needle, the slanted selector lever 60 must cooperate with a needle plate means ofwhich the configuration can be matched with the slanted selector lever 60.

With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the scope ofthe present invention. It is therefore intended that the invention be limited as indicated in the appended

Claims (7)

claims. CLAIMS

1. In a circular knitting machine, a needle selection mechanism for a needle cylinder having needle grooves on its periphery, each receiving a needle, and a needle plate means mounted below the needle, comprising: a selector block having at one side a plurality of elongated grooves spaced apart one above the other and extending horizontally; a plurality of selector levers receiving in the grooves respectively and mounted pivotally in the selector blockforturning about a vertical axis; solenoid-operated arms arranged one above the other and connected to the ends of the selector levers respectively to actuate selectively the selector levers, so asto put the needles in their operative positions or their in-operative positions; and a support for supporting the solenoid-operated arms.

2. A needle selection mechanism as claimed in Claim 1, wherein the selector block includes a vertical pivot member which passes through the grooves and the selector lever.

3. A needle selection mechanism as claimed in Claim 1, wherein the selector levers lie horizontally in the grooves.

4. A needle selection mechanism as claimed in Claim 1, wherein the selector levers are inciined relative to a horizontal plane.

5. A needle selection mechanism as claimed in Claim 1, in which the su pport includes a su pport bracket and a plurality of solenoid casings placed one above the other and secured to the support bracket.

6. A needle selection mechanism as claimed in Claim 5, wherein each of the solenoid-operated arms has a forked head extending out of the casing and pivoted to one end of each of the selector levers, a stem portion mounted movably in the casing, and a solenoid coil provided around the stem portion.

7. A needle selection mechanism as substantially described hereinbefore with reference to the accompanying drawings.