GB1590895A - Knitting machines - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO KNITTING MACHINES (71) I, BATTISTA MORENI, of Italian nationality, of Via Pila 3, Brescia, Italy, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The following invention relates to circular knitting machines, and particularly to means for selecting needles in a circular knitting machine during reciprocal knitting to knit -gussets such as heels in hosiery.

Conventionally, selection of needles to decrease and increase the number of stitches knit during reciprocal knitting is accomplished by the use of long and short butt needles and cams and members of various types acting on the needle butts. In a typical arrangement, the needles around one half of the needle cylinder have long butts and the needles around the other half of the needle cylinder have short butts. A switch cam is operated to raise the long butt needles with reciprocal knitting being accomplished on the short butt needles.During each reciprocation, a picker engages the leading short butt needle in each direction of reciprocal movement and raises it out of action to reduce the number of needles on which knitting takes place until a minimum number of needles are in action, following which adrop- per engages the leading short butt needles that are out of action in each direction of reciprocal movement and drops them back into action with the dropper dropping more needles back into action than the picker, which is continuing to operate, picks out of action until all of the short butt needles are back in action and reciprocal knitting is completed.

In this conventional operation, it is necessary to have two different types of needles, one type with long butts and the other type with short butts, which provides a cost and replacement disadvantage. Furthermore, there is a problem of damage of the relatively expensive needles by breakage of the butts due to the action of the cams and particularly the droppers and pickers, which have dorners at which the butts strike. This impact of the droppers and pickers with the needles also creates damage problems to the needle grooves of the needle cylinder in the areas in which the needles slide, which can cause defects in the knitting and a high cost of maintenance.

In contrast, the present invention eliminates the engagement of needle butts in the needle selection during reciprocal knitting and thereby eliminates the cost and damage problems associated with prior art needle selection during reciprocation. Thus, needles having butts all of the same length can be utilized and in one embodiment of the invention less expensive jacks can be used with long and hort butts to function with associated cams to accomplish needle selection.

According to the invention there is provided in a circular knitting machine having a needle cylinder with grooves in which needles, jacks and selectors are slidable and having cams engageable with butts on the needles, jacks and selectors to manipulate the needles for knitting, means for selecting needles to take part in reciprocal knitting comprising means for lowering at least one half of said jacks from an active position to an inactive position before reciprocal knitting and for maintaining one half of said jacks in said inactive position during reciprocal knitting to thereby not raise the corresponding needles for knitting, a raising cam having butt engaging surfaces facing in both directions or reciprocation and engageable with the butts of the jacks that are not in said inactive position to raise these jacks and corresponding needles for knitting, stitch cams on opposite sides of said raising cam and engageable with the butts of the raised needles to lower said needles to effect knitting in either direction of reciprocation, selecting members movable into the path of the jack butts for selectively engaging the jack butts to first move corresponding jacks selectively from said active position to said inactive position and to then selectively return these jacks to said active position and thereby selectively cause needles to become inactive or active during reciprocal knitting, and means for returning all of the jacks from said inactive position to said active position at the end of reciprocal knitting.

According to a preferred embodiment of the invention the jacks include short butt jacks and long butt jacks located in groups each around one half of the needle cylinder, and the means for lowering at least one half of the jacks comprise a switch cam engageable with the butts of the long butts jacks only.

Preferably, the aforementioned selecting members comprise means engageable with the leading short butt jacks in each direction of reciprocal movement to move the engaged jacks out of engagement with the corresponding needles and thereby not raise said needles for knitting, and means subsequently engageable with the leading short butt jacks in each direction of reciprocal movement to move them back.

In a preferred embodiment of the present invention, the selecting members comprise movable droppers on opposite sides of the raising cam beyond the circumferential location of the stitch cams and engageable with the butts of the leading short butt jacks in the respective directions of reciprocal movement and movable with the leading jacks to move the jacks to the inactive position, and a movable picker subsequently insertable into action to engage the butts of the leading short butt jacks in each direction of reciprocal movement to raise the short butt jacks to the active position and replace the corresponding needles into action.

The invention will now be described with reference to a preferred embodiment thereof illustrated in the accompanying drawings in which: Fig. 1 is a layout of cams of a segment of a circular knitting machine incorporating the preferred embodiment of the present invention with arrangements of needles, jacks and selectors at the left and right of the figure, and showing the cams in position during circular knitting; and Fig. 2 is a view similar to Fig. 1 showing the cams in position for needle selection during reciprocal knitting.

Referring to the accompanying drawings, the preferred embodiment of the means for selecting needles according to the present invention is incorporated in a conventional circular knitting machine 10 of which only the pertinent portion is shown, The portions not shown are of conventional construction and operation, including the needletcylinder in the grooves of which needles 12, jacks 14 and selectors 16 are vertically slidable to manipulate the needles for the knitting operation.

The needles 12 are of conventional construction and all of them have butts 18 of the same shape and size, which is an advantage from a cost and maintenance standpoint in comparison with the use of hneedles aving butts of different sizes. On the other hand, the jacks 14 are of two types, half of them having short butts 20, with these jacks being located around one half of the needle cylinder, and the other jacks have long butts 22 and are located around the other half of the needle cylinder. The selectors 16, which are only partially illustrated, have butts 24 for various needle manipulating functions of conventional nature.

Knitting by the needles 12 is accomplished by conventional stitch cams 26 and 28 acting on the needle butts 18 and with a raising cam 30 acting on jack butts 20 and 22 to raise the jacks 14 and corresponding needles 12 to a position for subsequent lowering to accomplish knitting in either direction of reciprocation. During circular knitting, the needle cylinder rotates the needles 12, jacks 14 and selectors 16 from left to right in Fig. 1 with the raising cam 30 engaging the jack butts 20 and 22 to raise the jacks 14 and corresponding needles 12. The needle butts 18 then engage the face of the stitch cam 28 at the right of Fig. 1, which causes the lowering of the needles 12 as the needle butts 14 travel down along the surface of the right stitch cam 28 to manipulate the needles for knitting of stitches in a conventional manner.

During reciprocal movement of the needle cylinder for reciprocal knitting, the right stitch cam 28 serves the same purpose as described for circular knitting during movement of the needles from left to right and the left stitch cam 26 in combination with the raising cam 30 performs the same function during movement of the needles from right to left.

With this arrangement the raising cam 30 has butt engaging surfaces 32 and 34 facing in both directions of reciprocation and the stitch cams 26 and 28 are disposed on opposite sides of the raising cam 30, but in the path of the needle butts 18 whereas the raising cam surfaces 32 and 34 are in the path of the jack butts 20 and 22, which is a conventional arrangement.

To select needles to take part in reciprocal knitting according to the present invention there are provided means for lowering at least one half of the jacks from an active position to an inactive position before reciprocal knitting and for maintaining one half of the jacks in the inactive position during reciprocal knitting to thereby not raise the corresponding needles for knitting.

In the preferred embodiment shown in the drawings the means for lowering the jacks comprise a switch cam 36 mounted for radial movement in the path ofjack butts 20 and 22 in advance of the raising cam 30, which is to the left in the accompanying drawings.

This switch cam 36 has a jack butt engaging surface 38 inclined downwardly to the right, i,e. downwardly in the direction of circular knitting. During circular knitting, the switch cam 36 is retracted radially out of the path of all of the jack butts 20 and 22 to permit the jacks 14 to be acted on by the raising cam 30. The switch cam 36 is inserted by conventional cam manipulating means when reciprocal knitting takes place to a position in which the switch cam surface 38 does not engage the short butts 20 of the jacks 14, but does engage the long butts 22 and causes lowering of the long butt jacks as the jacks move from left to right, thus lowering out of action the long butt jacks into the inactive position, which results in the corresponding needles remaining at their inactive level as their associated jacks do not engage the raising cam 30 to effect raising of the needles.

The jacks 14 with the short butts 20 are not lowered by the switch cam 36, but continue at an active level for engagement by the raising cam 30 to raise the associated needles 12 for subsequent knitting manipulation by the right stitch cam 28. As the long butt jacks are out of action, continued reciprocal movement will cause knitting only on the needles associated with the short butt jacks.

During reciprocal knitting it is necessary to decrease the number of needles knitting in each reciprocal movement until a desired minimum number of needles remain and then to increase the number of needles until all of the needles associated with short butt jacks are again knitting. This selection of needles for decreasing and increasing the number of needles during reciprocation is accomplished by selecting members comprising droppers 40 and 42 and a picker 44. These members are insertable radially from retracted positions out of the path of the jack butts 20 and 22 during circular knitting and into the path of the jack butts during reciprocal knitting for selectively engaging the jack butts to first move corres ponding jacks selectively from the active position to the inactive position and to then selectively return these jacks to the active position.

The droppers 40 and 42 are located on opposite sides and at spacings from the raising cam 30 beyond the circumferential location of the stitch cams 26 and 28 in the path of the butts of active jacks. The left dropper 40 is disposed between the raising cam 30 and the switch cam 36 and has a needle engaging recess 45 facing to the left to receive the butt 20 of the leading short butt jack 14 during reciprocal movement from left to right. This dropper is movable with the leading jack and is pivoted so that the movement results in downward movement of the butt 20 of the leading jack from the active path 46 to the inactive path 48 along a line indicated generally as 50.This results in the leading jack moving out of engagement with the corresponding needle and the needle associated with the leading jack remaining inactive as the jack is not raised by the raising cam 30 to elevate the needle 12 for knitting. The dropper 42 at the right is similarly formed with a jack butt engaging recess 52 facing to the right for similar engagement of the butt 20 of the leading short butt jack 14 during reciprocal movement from right to left. These droppers 40 and 42 are manipulated in the same way as conventional droppers are used to engage needle butts and move needles from inactive to active position during conventional reciprocal knitting.

The aforementioned picker 44 is disposed to the right of the right dropper 42 and is normally disposed in the path of the butts of jacks in the inactive position. This picker 44 remains in its retracted position out of contact with jack butts during circular knitting and during the first half of reciprocal knitting when the droppers 40 and 42 are progressively decreasing the number of needles in action.

When the minimum number of needles in operation has been reached, the picker 44 is inserted into the path of the butts of jacks in inactive position. The picker 44has recesses 54 on opposite sides thereof for receipt of the butts of two leading shortbutt jacks during reciprocation in each direction and is movable with the jack butts in engagement to raise the jacks back to the active position and replace the corresponding needles into action. Thus, as the jacks move from left to right, the butts of the leading two short-butt jacks in the inactive path 48 are engaged by the picker 44 and moved to the right and upwardly into the active path 46, and during reciprocal movement from right to left the butts of the leading two inactive short-butt jacks are similarly raised by the picker 44 by movement upwardly to the left into the active path 46.

The control and manipulation of the picker 44 is the same as is conventionally used with pickers to raise needles from active to inactive positions in conventional reciprocating operations.

During operation of the picker 44, the droppers 40 and 42 remain in operation so that the picking of two jacks and the dropping of one jack during each reciprocation will result in a net increase of one jack and associated needle into knitting action.

After reciprocal knitting is completed, a conventional cam can be inserted to engage the butts of all of the jacks 14 in the inactive position to return these jacks 14 back to the active position for resumption of circular knitting.

Alternatively, the selectors 16 may be manipulated through their butts 24 to raise all of the jacks and needles to knitting position. These selectors could also be used with a switch cam like cam 36 to raise the short butt jacks into active position during reciprocation after all jacks have been lowered by the switch cam and to raise all of the jacks during circular knitting. In other words, the switch cam would engage the butts of all jacks to lower them, and another cam would be provided to subsequently raise the selectors 16 corresponding to the jacks whose needles have to knit during reciprocal movement, such as to bring these latter jacks to the active position at the beginning of reciprocal knitting.Raising of the jacks and needles to resume circular knitting as well as raising thereof during circular knitting would also be accomplished by the selectors by means of suitable cams.

From the foregoing description it is apparent that the needles are free of engagement by selecting members such as the droppers 40 and 42 and the picker 44, with the elimination of the problem of butt breakage and groove damage that results with conventional selecting member engagement with needles butts. There is, of course, the possibility of damage of jack butts, but jacks are less expensive than needles and there is no damage to the grooves in the needle area when jack butts are damaged. Furthermore, only one size of needle is necessary for repair and maintenance.

WHAT I CLAIM IS: 1. In a circular knitting machine having a needle cylinder with grooves in which needles, jacks and selectors are slidable and having cams engageable with butts on the needles, jacks and selectors to manipulate the needles for knitting, means for selecting needles to take part in reciprocal knitting comprising means for lowering at least one half of said jacks from an active position to an inactive position before reciprocal knitting and for maintaining one half of said jacks in said inactive position during reciprocal knitting to thereby not raise the corresponding needles for knitting, a raising cam having butt engaging surfaces facing in both directions of reciprocation and engageable with the butts of the jacks that are not in said inactive position to raise these jacks and corresponding needles for knitting, stitch cams on opposite sides of said raising cam and engageable with the butts of the raised needles to lower said needles to effect knitting in either direction of reciprocation, selecting members movable into the path of the jack butts for selectively engaging the jack butts to first move corresponding jacks selectively from said active position to said inactive position and to then selectively return these jacks to said active position and thereby selectively cause needles to become inactive or active during reciprocal knitting, and means for returning all of the jacks from said inactive position to said active position at the end of reciprocal knitting.

2. Means for selecting needles in a circular knitting machine as claimed in claim 1, wherein said jacks include short butt jacks and long butt jacks located in groups each around on half of the needle cylinder, and wherein said means for lowering at least one half of said jacks comprise a switch cam engageable with the butts of said long butt jacks only.

3. Means for selecting needles in a circular knitting machine as claimed in claim 1, wherein said means for lowering at least one half of said jacks comprise a switch cam for engaging the butts of all the jacks, and a cam for raising the selectors corresponding to the other half of the jacks to bring these latter jacks to said active position at the beginning of reciprocal knitting.

4. Means for selecting needles in a circular knitting machine according to claims 1 and 2, wherein said selecting members comprise means engageable with the leading short butt jacks in each direction of reciprocal movement to move the engaged jacks out of engagement with the corresponding needles and thereby not raise said needles for knitting, and means subsequently engageable with said leading short butt jacks in each direction of reciprocal movement to move them back.

5. Means for selecting needles in a circular knitting machine according to claims 1 and 2, wherein said selecting members comprise movable droppers on opposite sides of said raising cam beyond the circumferential location of said stitch cams and engageable with the butts of the leading short butt jacks in the respective directions or reciprocal movement and movable with said leading jacks to move said jacks to said inactive position, and a movable picker subsequently insertable into action to engage the butts of said leading short butt jacks in each direction of reciprocal movement to raise said short butt jacks to said active position and replace the corresponding needles into action.

6. Means for selecting needles in a circular knitting machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. with a switch cam like cam 36 to raise the short butt jacks into active position during reciprocation after all jacks have been lowered by the switch cam and to raise all of the jacks during circular knitting. In other words, the switch cam would engage the butts of all jacks to lower them, and another cam would be provided to subsequently raise the selectors 16 corresponding to the jacks whose needles have to knit during reciprocal movement, such as to bring these latter jacks to the active position at the beginning of reciprocal knitting. Raising of the jacks and needles to resume circular knitting as well as raising thereof during circular knitting would also be accomplished by the selectors by means of suitable cams. From the foregoing description it is apparent that the needles are free of engagement by selecting members such as the droppers 40 and 42 and the picker 44, with the elimination of the problem of butt breakage and groove damage that results with conventional selecting member engagement with needles butts. There is, of course, the possibility of damage of jack butts, but jacks are less expensive than needles and there is no damage to the grooves in the needle area when jack butts are damaged. Furthermore, only one size of needle is necessary for repair and maintenance. WHAT I CLAIM IS:

1. In a circular knitting machine having a needle cylinder with grooves in which needles, jacks and selectors are slidable and having cams engageable with butts on the needles, jacks and selectors to manipulate the needles for knitting, means for selecting needles to take part in reciprocal knitting comprising means for lowering at least one half of said jacks from an active position to an inactive position before reciprocal knitting and for maintaining one half of said jacks in said inactive position during reciprocal knitting to thereby not raise the corresponding needles for knitting, a raising cam having butt engaging surfaces facing in both directions of reciprocation and engageable with the butts of the jacks that are not in said inactive position to raise these jacks and corresponding needles for knitting, stitch cams on opposite sides of said raising cam and engageable with the butts of the raised needles to lower said needles to effect knitting in either direction of reciprocation, selecting members movable into the path of the jack butts for selectively engaging the jack butts to first move corresponding jacks selectively from said active position to said inactive position and to then selectively return these jacks to said active position and thereby selectively cause needles to become inactive or active during reciprocal knitting, and means for returning all of the jacks from said inactive position to said active position at the end of reciprocal knitting.

2. Means for selecting needles in a circular knitting machine as claimed in claim 1, wherein said jacks include short butt jacks and long butt jacks located in groups each around on half of the needle cylinder, and wherein said means for lowering at least one half of said jacks comprise a switch cam engageable with the butts of said long butt jacks only.

3. Means for selecting needles in a circular knitting machine as claimed in claim 1, wherein said means for lowering at least one half of said jacks comprise a switch cam for engaging the butts of all the jacks, and a cam for raising the selectors corresponding to the other half of the jacks to bring these latter jacks to said active position at the beginning of reciprocal knitting.

4. Means for selecting needles in a circular knitting machine according to claims 1 and 2, wherein said selecting members comprise means engageable with the leading short butt jacks in each direction of reciprocal movement to move the engaged jacks out of engagement with the corresponding needles and thereby not raise said needles for knitting, and means subsequently engageable with said leading short butt jacks in each direction of reciprocal movement to move them back.

5. Means for selecting needles in a circular knitting machine according to claims 1 and 2, wherein said selecting members comprise movable droppers on opposite sides of said raising cam beyond the circumferential location of said stitch cams and engageable with the butts of the leading short butt jacks in the respective directions or reciprocal movement and movable with said leading jacks to move said jacks to said inactive position, and a movable picker subsequently insertable into action to engage the butts of said leading short butt jacks in each direction of reciprocal movement to raise said short butt jacks to said active position and replace the corresponding needles into action.

6. Means for selecting needles in a circular knitting machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.