US3877258A

US3877258A - Apparatus for controlling the automatic selection of sinkers in circular knitting machines

Info

Publication number: US3877258A
Application number: US297388A
Authority: US
Inventors: Pavel Uhlir
Original assignee: Elitex Zavody Textilniho
Current assignee: Elitex Zavody Textilniho
Priority date: 1971-10-14
Filing date: 1972-10-13
Publication date: 1975-04-15
Anticipated expiration: 1992-04-15
Also published as: CS160788B1; DE2248898A1; DE2248898C2; IT968674B; GB1382289A; FR2157494A5

Abstract

A circular knitting machine having a rotary cylinder in which a plurality of needles are mounted and a plurality of ground and plush loop sinkers each of the latter sinker type having an edge for forming plush loops. Each sinker is mounted to be associated with a respective one of the needles and movable into an operative position in cooperation with the associated needle to catch the yarn laid thereon. Patterning means are provided having a predetermined program for selecting one of said sinkers to be moved into operative position. Included are transmission means for transferring the program to the selected sinker. At least a portion of the transmission means is located within an axial groove in the needle cylinder.

Description

United States Patent Uhlil Apr. 15, 1975 2,734,361 Blais 66/108 R AUTOMATIC SELECTION OF SINKERS IN 3,293,887 12/1968 Crawford 66/93 3,394,564 7/1968 Brook 66/93 CIRCULAR KNITTING MACHINES Pavel Uhlir, Trebic, Czechoslovakia Assignee: Zavody textiliniho strojirenstvi, generalni reditelstvi Elitex, Liberec, Czechoslovakia Filed: Oct. 13, 1972 Appl. N0.: 297,388

Inventor:

[30] Foreign Application Priority Data Oct. 14, 197i Czechoslovakia 7212-71 US. Cl 66/93; 66/107 Int. Cl D04b 15/06 Field of Search 66/93, 107, 108 R, 108 A,

References Cited UNITED STATES PATENTS 2/1939 Horrocks .66/93 3/1942 Smith ..66/93 Il -1. my. a

Primary ExaminerW. C. Reynolds Assistant ExaminerA. M. Falik Attorney, Agent, or Firm-Murray Shaffer 5 7] ABSTRACT A circular knitting machine having a rotary cylinder in which a plurality of needles are mounted and a plurality of ground and plush loop sinkers each of the latter sinker type having an edge for forming plush loops. Each sinker is mounted to be associated with a respective one of the needles and movable into an operative position in cooperation with the associated needle to catch the yarn laid thereon. Patterning means are provided having a predetermined program for selecting one of said sinkers to be moved into operative position. Included are transmission means for transferring the program to the selected sinker. At least a portion of the transmission means is located within an axial groove in the needle cylinder.

12 Claims, 9 Drawing Figures PATENIEBAPRI sms 3'. 877. 258

sum 2 (if 5 52 I I I I I I m l 4 APPARATUS FOR CONTROLLING THE AUTOMATIC SELECTION OF SINKERS IN CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION The present invention relates to a device for selecting sinkers in circular knitting machines. particularly sinkers for forming plush loops.

One of the methods hitherto known to solve the above problem employs a plurality of butts located at various heights on the sinkers. The control butts are guided by a cam system located in the cover of the sinker ring assembly. Some cams of this cam system are axially movable and are controlled for example from a control drum. in such manner. that upon being set in their operative position. the cams co-operate only with certain butts located at a certain height. the course of the path of the appurtenant sinkers being thus changed.

The aforementioned techniques. however. do not allow change of the control butts for different denier sizes. and can thus be used only for rib effect on plush knitwork.

Another known device solves this problem in'such manner that in addition to the sinker ring. there is mounted a special patterning drum, on which a program is made which is scanned by movable arms cooperating with the control butts mounted at various heights on a selector which is mounted together with the sinker in the groove of a sinker ring. The selector creates a certain coincidence of the control butt and a lever causing the sinker to move into contact with a cam system which moves the sinker into an operative position.

The latter device makes possible the performance of a successive selection of sinkers into operation, whereby it is possible to make several patterns on the knitwork. However. the extent of such a manner of patterning upon knitting plush is considerably limited. as the patterning device can only be mounted within the space around the sinker ring. with great difficulty. As a consequence patterning possibilities are severely limited. Moreover. it is necessary to provide in that device a special patterning drum.

It is the object of the present invention to provide apparatus which overcomes the disadvantages of the prior art devices.

It is another object of the present invention to provide means for selecting predetermined sinkers which is simple. and reliable in operation and which does not require extensive revision or modification of existing knitting machines.

These and other objects as well as numerous advantages of the present invention will be seen from the foregoing description.

SUMMARY OF THE INVENTION According to the present invention there is provided a circular knitting machine having a rotary cylinder in which a plurality of needles are mounted and a plurality of ground and plush loop sinkers each of the latter sinker type having an edge for forming plush loops. Each sinker is mounted to be associated with a respective one of the needles and movable into an operative position in cooperation with the associated needle to catch the yarn laid thereon. Patterning means are provided having a predetermined program for selecting ones of said sinkers to be moved into operative position. Included are transmission means for transferring the program to the selected sinker. At least a portion of the transmission means is located within an axial groove in the needle cylinder.

Preferably, the transmission means comprises a se Iector jack. an auxiliary jack. and a blocking member having means for engaging the sinker to stop the sinker movement. In one embodiment the blocking member and the needle are the same. while in another member they are separate.

Further. the sinkers are formed with means to allow them to ride in the supporting sinker groove or to be limited in its movement by engaging the edge of the cam ring. A rocker cam is provided by cause the sinker to ride through several gradient levels.

Full details of the present invention follow herein and are shown in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawings:

FIG. 1 represents the arrangement of sinkers. needles auxiliary jacks and selector jacks, cam system and a patterning device. in a circular knitting machine shown in section through vertical plane passing through the axis of the needle cylinder;

FIG. 2 a developed cam system for controlling the selector jacks. the auxiliary jacks and the needles and a developed cam system for controlling sinkers forming plush loops, said cam system being tilted for better representation by an angle of 90 and its rocker cam being shown in a section plane as given by arrows GG;

FIG. 3 a view in the direction of the arrows on the section plane A-A as shown in FIG. 2;

FIG. 4 a view in the direction of the arrows on the section plane B-B as shown in FIG. 2;

FIG. 5 a view in the direction of arrows on the section plane C-C as shown in FIG. 2;

FIG. 6 a view in the direction of the arrows on the plane D-D as shown in FIG. 2;

FIG. 7 a view in the direction of the arrows on the section plane E-E as shown in FIG. 2;

FIG. 8 a view in the direction of the arrows on the section plane FF as shown in FIG. 2;

FIG. 9 is an exploded view showing a needle and separate blocking jack.

DESCRIPTION OF INVENTION Turning to FIG. I there is depicted a rotary cylinder machine for knitting tubular articles such as socks. The needle cylinder 1 is rotatably mounted on a ball bearing 2 arranged in an upper flange 3 and on a ball bearing 4 arranged in a lower flange 5 of the supporting machine frame. The ball bearing 2 consists of an outer ring 2a. an inner ring 2b and balls 20. The

rings

2a and 2b are L-shaped in cross section and provide a combined radial and axial thrust bearing. The ball bearing 4 consists of an outer ring 4a. which is fixedly connected with flat mounting ring 4h secured to the flange 5, an inner ring 4c and balls It. The inner ring 40 is T-shaped in cross section to support two axial rows of balls 4 while the outer ring 4a is L-shaped, thus providing. here also axial and radial thrust components. A bevel gear 9 is mounted by means of screws 6 and pins 7 to the lower end of cylinder I. The bevel gear is in engagement witl a meshing driving bevel gear 10, which is itself driver by a not shown electric motor. Inside the needle cylinder 1, is arranged a stationary tubular insertion ll having a flared upper end or verge through which the work piece may be removed.

A stand I2 is mounted on the lower flange 5 and a pin 13 on which a patterning drum I4 is rotatably mounted is secured thereto. The drum I4 is provided with a selecting program by means of pins 15. which cooperate with patterning arms 16. The patterning drum 14 is advanced by a not shown pawl which is mounted on lever 17, engaging the teeth of ratchet I8 formed at the lower end of patterning drum 14. The patterning drum is indexed, that is, programmed to bring selected sinkers to a working position. by connection to a conventional pattern control mechanism and on rotation is adapted to cause one or more of the pins I5 to engage their associated arms 16 moving the arms 16 radially into corresponding engagement with the needle selector jacks.

Mounted oppositely to the patterning arms 16, inside each of the longitudinal needle tricks or grooves 19 of needle cylinder 1, are selector jacks. one jack being identified by numeral 20 and each of which are provided with a selecting butt 21 and a pair of control butts 22 and 23. The control butts 22 and 23 are guided in a cam system which consists of a lower cam ring 24 and an upper cam ring 25, contoured as seen in FIG. 2. The cam ring 24 is fixedly connected with mounting ring 412 of bearing 4 by means of screws 26 to the lower flange 5 of the machine frame. Cam ring is mounted. by means of screws. to an annular bracket cam carrier 27, which is fastened by screws 28 to the upper flange 3. Above each of the selector jacks 20 inside grooves 19 of needle cylinder 1 there is mounted an auxiliary sinker jack 29 which is also provided with a control butt 30 operated by means of a second set of cam rings 31 and 32. The

cams

31 and 32 form a split annular ring and are contoured as seen in FIG. 2. Set above cam 25 to cooperate with earns 31 and 32, is a radially movable cam piece 33. The cam rings 31 and 32 are fastened by means of screws or the like, to cam carrier 27, (FIG. I.)

Above each of the auxiliary sinker jacks 29, there is mounted a needle 34 inside grooves 19. The needles 34 are arranged and movably secured in their associated trick by circular springs 35. Each needle has a control butt 36 operated by

cams

37, 38, 39 (FIG. 2) which are fixedly mounted on a second cam carrier 40 which is fastened by screws 41 to the upper flange 3 of the machine frame. Each needle 34 is provided with contact surfaces 42 and adapted to cooperate with a laterally bent butt 43, (FIGS. 2 and 3) on an associated plush sinker 44 which is provided with a knock over edge 45 for forming plush loops. The plush loop sinker 44 together with another sinker 48 for forming the current or running loops, that is. the ground loops are mounted insideia groove 46 of a sinker ring 47. Further. the sinker 44 by which the plush loops are formed, is provided with a control butt 49 (FIG. 3) which cooperates with a sinker cam ring 50, fixedly connected with the dial lid 51.

Each plush sinker 44 extends beyond the control butt 49, to form a foot 52 made to cooperate with a rocker cam 53 which is mounted by screws 54 to the sinker assembly cover 51. The rocker cam 53 extends below the annular hollow and thus the opening in groove 46 of sinker ring 47 and is arranged at a distance from the edge of the bottom of groove 46 which is shorter than the length of the end of the sinker cam ring 47 beginning from the vertical edge of the sinker recess. Extending from the lower side of each of the sinkers 44 is a projection 55, to which one end of an extension spring 56 is mounted. the other end of which is mounted on a washer 57 which is fastened by screw 58 to the under side of the sinker ring 47. A recess 59 is made on sinker 44 in front of the projection 55 so that the sinker 44 may be guided by its horizontal edge along the bottom of the groove 46 of sinker ring 47 and by its vertical edge the sinker 44 may be locked and held in an inoperative position behind the edge of groove 46 (FIG. 7) of sinker ring 47. In addition to groove 46, the sinker 44 is guided freely along the step In (FIG. 7) of needle cylinder 1.

The operation of the device as specified above is as follows:

In general the machine operates in conventional manner, yarn being fed to the needles, which are moved reciprocally up and down in the grooves or tricks. while the sinkers are operated to reciprocate in a horizontal direction in cooperation with the needles to form the necessary loops. The sinkers 48 are adapted to form the ground or running loop while selected sinkers 44 are adapted to form the plush loop. The basis for selecting sinkers 44 for forming the plush loops is the division of the needles 34 into two mutually different heights. To this end the needle cylinder 1 is rotated in the direction of arrow S (FIG. 2) entraining therewith the associated selector jacks 20, auxiliary sinker jacks 29 and the needles 34. Simultaneously, the patterning drum is indexed, and the control pins I5 operated in dependence on the preselected program to cause one or more of the associated arms 16 to extend within the vertical path described by the butts 21. The selector jack 20, which has its selecting butt 21 at that height corresponding to the extension of patterning arm 16, contacts the patterning arm and is pressed deeper into groove 19, thus causing the jack to carry the control butts 23 into an inactive position out of range of cam ring 24. Thus. the control butts 22 and 23 of selector jacks 20 move along straight horizontal paths 22a and 2311 (FIG. 2). The selector jacks 20, which have not been selected, or pressed into inactive position by contact with an arm 16 have their control butts 23 touching the lifting edge of cam ring 24 and thus cause their control butts 22 and 23- to move about paths 22b and 23b. Simultaneously, the appurtenant auxiliary jacks 29 associated with the active jacks 20 are lifted. so that the control butts 30 move about path 3012 while the appurtenant needles 34 are also lifted, so that their control butts 36 move about path 36b. The remaining auxiliary jacks 29, associated with the inactive jacks 20 have their control butts 30, lifted via path 30a on the radially movable cam 33 into the linearly horizontal path 30h. Analogously. the control butts 36 of each needle 34 are lifted about path 36a into the path 36b. Upon further turning of needle cylinder 1, the control butts 36 of needles 34 are lifted about path 36b on cam 37 and cleared by cam 38 in such manner. that these needles 34 are in a clearing position as shown in FIG. 3. The plush loop sinkers 44 follow with their control butts 49 and the cam ring at a height-u and the feet 52 of the plush loop sinkers 44 follow the horizontal edge of rocker cam 53.

Upon clearing the control butts 36 of needles 34 on cam 38. the control butts 23'of non selected or active selector jacks 20, have been lifted about path 2312 on cam ring 24. Thus, control butts 22 move about path 22b and the control butts 30 of auxiliary sinker'jacks 29 move about path 300. until all needles 34 are in their clearing position. Upon further turning of needle cylinder 1, the auxiliary jacks 29 come into contact with needles 34 and lift them, i.e. control butts 36 follow the path 360. into a higher clearing position as shown in FIG. 4, so that the contact surface 42 or stop means acting like a blocking jack is situated within the path of the laterally bent butt 43 of sinker 44 blocking further movement of the sinker 44. Thus. needles 34 are divided into two different positions namely a low and high clearing position. In the following course of rotation control butts 22, 23 and 30 further slide about paths 22b, 23b and 30c on the clearing edges of cam ring and cam ring 32 to the initial starting position.

Those needles 34 in the low clearing position permit passage of sinkers 44, as shown in FIGS. 5 and 8 into an operative position for the purpose of drawing in yarn over edge 45. Thus the control butts of auxiliary jacks 29 pass along path 300, and control

butts

22 and 23 of selector jacks 20 move about paths 22a and 23a. The control butts 49 of the sinkers 44 follow the first dropping edge of cam 50 from height a to height d, passing over an' edge of zero gradient at height d and a further dropping gradient edge from height d to e. Thus. the sinker 44 is guided about a horizontal edge of recess 59 along the bottom of groove 46 of sinker ring 47 as shown in FIG. 8.

Simultaneously, upon movement of plush loop sinker 44 into its operative position, those inactive sinkers 44 which have been selected by the patterning device, are blocked by needles 34, which have been lifted into a higher clearing position. As seen. the selector sinker 44 follows the first gradient edge of the sinker cam ring 50 as high as height h at which time the laterally bent blocking butt 43 contacts the contact butt 42 of needle 34 and the selected sinker 44 is held by extension spring 56 on needle 34. Simultaneously, the foot 52 contacts the gradient edge of the rocker cam 53 and by means of extension spring 56, causes the sinker 44 to to be pivoted slightly counter-clockwise and to cause the vertical edge ofthe recess 59 to grip, at height 0. the edge of the groove 46 of the sinker ring 47, as shown in FIG. 7. Simultaneously, needle 34 is cleared by its control butt 36 about the path 366 by means of cam 38 to return back to path 3612.

Upon further turning of needle cylinder 1, yarn is laid by conventional means into the hooks of the needles 34 and over the clearing edges 45 of the selected sinkers 44 and over the operative edges of sinkers 48. The needles 34 are cleared on cam 39. Sinker plush loops are made on sinkers 44 while ground loops are knocked over on the sinkers 48. As seen in FIGS. 6 and 7, the sinker 48 is independently mounted in a groove directly behind the plush sinker 44 and no stop or deflection means 43 on the plush sinker is needed. As seen in FIG. 7, the mutual positioning of the plush sinker 44, the knocking over sinker 48 and the needle in a lowered position is such that the basic yarn caught by the needle is cleared over the edge of both sinker 44 and sinker 48. Thus. the ground loop is formed.

Selection of a plush sinker in accordance with the invention is analogous. However. the final element for selection control that is, element 43 has only a selecting function and not a blocking function and is not mounted in the axial groove of the needle cyliner.

The same result may be achieved also. as seen in FIG. 9. by placing the contact surface 42 on a special blocking jack 42a below which are also arranged an auxiliary jack and a selector jack. The position of the butts may be obtained with another gauging or with the same gauging. These jack elements are located inside a parallel longitudinal groove in needle cylinder 1 lying beside groove 19 in which the needle is mounted. The jacks are controlled by the same cam system. The patterning device can be the same as for selecting the needles or it can control only the selection of blocking sinkers. the needles being selected by means of the cam system. Furthermore, the present invention is not limited only to a single cylinder knitting machine. but may be eniployed on a double cylinder machine.

The main advantage of the present invention consists in that it makes possible the use of conventional patterning devices, or patterning drums. respectively which may be mounted beside the lower half of the needle cylinder. The invention allows the production of hosiery goods in a single color with a synthetic yarn or in a multi color pattern with colored plush loops.

What is claimed is:

l. A circular knitting machine comprising a rotary cylinder, having a plurality of axial grooves, a plurality of needles mounted for axial movement in said cylinder, a plurality of associated ground loop sinkers and plush loop sinkers mounted in a sinker ring. each of said plush loop sinkers having an operative edge for forming plush loops, each of said sinkers being associated with a respective one of said needles and movable horizontally into an operative position in cooperation with said associated needle to catch the yarn laid therein. patterning means having a predetermined program for determining selected ones of said plush loop sinkers to be moved into operative position and means associated with each plush loop sinker for transmitting said program to said selected sinkers for controlling their horizontal movement. at least a portion of said means for transmitting said program being located within an axial groove of said needle cylinder.

2. The machine according to claim 1 wherein said means for transmitting said program comprises a selector jack movable by said patterning means, an auxiliary jack movable by said selector jack, and stop means movable by said auxiliary jack into engagement with said plush sinker whereby movement of said plush sinker into its operative position is blocked.

3. The machine according to claim 2 including cam means for lifting said stop means into a first position permitting operation of said plush sinkers and into a second position, higher than said first position. blocking said operation, said patterning means acting to cause said stop means to be moved into contact with said cam means to be raised to said higher position.

4. The machine according to claim 3 wherein said stop means is formed on said needle. and said selector jack. auxiliary jack and needle are mounted in a common groove.

5. The machine according to claim 2 wherein said stop means comprises a blocking jack and wherein said blocking jack. auxiliary jack, and selector jack are mounted on said cylinder in a groove parallel to said needle.

6. The machine according to claim 3 wherein said selector jack is provided with a radially extending butt and wherein said patterning means comprises a rotating drum and means adapted to project from said drum at selected lengths. said drum being mounted adjacent said rotary cylinder with said projecting means abutting the butts of said selector jack. to move said selector jack and to cause said selector jack to move out of engagement with the selected ones of said cam means.

7. The machine according to claim 3 wherein said sinkers are each supported in a radial groove formed in an annular sinker ring. and includes an annular rocker cam spaced therefrom. each of said plush sinkers formed with a recess defining a horizontal edge and a vertical edge. a projection depending below the plane of said groove to the rear of said recess and a foot extending from the rear of said projection, said foot being adapted to ride on said rocker cam. said rocker cam having a contour selectively moving said sinker into a first position wherein said horizontal edge rides on the bottom of said groove. and a second position wherein said vertical edge abuts against the edge of said sinker ring.

8. The machine according to claim 7 including spring means for resiliently biasing each of said plush sinkers urging said plush sinker downwardly into said associated groove.

9. The machine according to claim 4 wherein a sinker cam ring having a groove for each sinker is provided in the direction of rotation of the needle cylinder with a gradient edge. which is interrupted by an edge of zero gradient as far as the point. at which the plush sinker is in its operative position, said stop means being situated at this point and out of contact with the associated plush sinkers.

10. The machine according to claim 9 wherrein at the point at which the first gradient edge of said sinker cam ring is situated a rocker cam is arranged said plush sinker having a recess riding in the groove of said sinker ring cam and a foot guided on said rocker cam. the point of the zero gradient edge of said sinker cam ring corresponding to the gradient edge of said rocker cam which causes lowering of said foot and thus sinking of the horizontal edge of said recess below the level of grooves of the plush sinker cam ring when the sinker is blocked. and said gradient edge is continued by a horizontal edge which begins at the point at which ends the zero gradient edge.

11. The machine according to claim 10 wherein at the point corresponding to the zero gradient edge of the sinker cam ring. the needles associated with the blocked sinkers are raised to a higher position by a cylinder raising cam than the other needles. thereby causing said needles associated with the blocked sinkers to block the associated sinkers from further movement into operative position.

12. The machine according to claim 11 wherein the edge of the rocker cam. about which said foot is guided. is arranged at such a distance from the edge of the bottom of said grooves of said sinker cam ring. said distance being shorter than the length ofthe end of said sinker cam ring beginning from the vertical edge of said sinker recess.

Claims

1. A circular knitting machine comprising a rotary cylinder, having a plurality of axial grooves, a plurality of needles mounted for axial movement in said cylinder, a plurality of associated ground loop sinkers and plush loop sinkers mounted in a sinker ring, each of said plush loop sinkers having an operative edge for forming plush loops, each of said sinkers being associated with a respective one of said needles and movable horizontally into an operative position in cooperation with said associated needle to catch the yarn laid therein, patterning means having a predetermined program for determining selected ones of said plush loop sinkers to be moved into operative position and means associated with each plush loop sinker for transmitting said program to said selected sinkers for controlling their horizontal movement, at least a portion of said means for transmitting said program being located within an axial groove of said needle cylinder.

3. The machine according to claim 2 including cam means for lifting said stop means into a first position permitting operation of said plush sinkers and into a second position, higher than said first position, blocking said operation, said patterning means acting to cause said stop means to be moved into contact with said cam means to be raised to said higher position.

4. The machine according to claim 3 wherein said stop means is formed on said needle, and said selector jack, auxiliary jack and needle are mounted in a common groove.

5. The machine according to claim 2 wherein said stop means comprises a blocking jack and wherein said blocking jack, auxiliary jack, and selector jack are mounted on said cylinder in a groove parallel to said needle.

6. The machine according to claim 3 wherein said selector jack is provided with a radially extending butt and wherein said patterning means comprises a rotating drum and means adapted to project from said drum at selected lengths, said drum being mounted adjacent said rotary cylinder with said projecting means abutting the butts of said selector jack, to move said selector jack and to cause said selector jack to move out of engagement with the selected ones of said cam means.

7. The machine according to claim 3 wherein said sinkers are each supported in a radial groove formed in an annular sinker ring, and includes an annular rocker cam spaced therefrom, each of said plush sinkers formed with a recess defining a horizontal edge and a vertical edge, a projection depending below the plane of said groove to the rear of said recess and a foot extending from the rear of said projection, said foot being adapted to ride on said rocker cam, said rocker cam having a contour selectively moving said sinker into a first position wherein said horizontal edge rides on the bottom of said groove, and a second position wherein said vertical edge abuts against the edge of said sinker ring.

9. The machine according to claim 4 wherein a sinker cam ring having a groove for each sinker is provided in the direction of rotation of the needle cylinder with a gradient edge, which is interrupted by an edge of zero gradient as far as the point, at which the plush sinker is in its operative position, said stop means being situated at this point and out of contact with the associated plush sinkers.

10. The machine according to claim 9 wherrein at the point at which the first gradient edge of said sinker cam ring is situated a rocker cam is arranged said plush sinker having a recess riding in the groove of said sinker ring cam and a foot guided on said rocker cam, the point of the zero gradient edge of said sinKer cam ring corresponding to the gradient edge of said rocker cam which causes lowering of said foot and thus sinking of the horizontal edge of said recess below the level of grooves of the plush sinker cam ring when the sinker is blocked, and said gradient edge is continued by a horizontal edge which begins at the point at which ends the zero gradient edge.

11. The machine according to claim 10 wherein at the point corresponding to the zero gradient edge of the sinker cam ring, the needles associated with the blocked sinkers are raised to a higher position by a cylinder raising cam than the other needles, thereby causing said needles associated with the blocked sinkers to block the associated sinkers from further movement into operative position.

12. The machine according to claim 11 wherein the edge of the rocker cam, about which said foot is guided, is arranged at such a distance from the edge of the bottom of said grooves of said sinker cam ring, said distance being shorter than the length of the end of said sinker cam ring beginning from the vertical edge of said sinker recess.