US3449928A

US3449928A - Selector apparatus for circular knitting machines

Info

Publication number: US3449928A
Application number: US532304A
Authority: US
Inventors: Richard Schmidt; Hans-Joachim Stock
Original assignee: Franz Morat GmbH
Current assignee: Franz Morat GmbH
Priority date: 1965-03-06
Filing date: 1966-03-07
Publication date: 1969-06-17
Anticipated expiration: 1986-06-17
Also published as: AT312147B; NL7512891A; NL7512890A; SE327038B; NL7512892A; IL25226A; CH521460A; SE341044B; GB1112599A; BE677251A; SE341045B; DE1585215A1; US3561232A; NL6602736A; CH433566A; SE352385B; CS150998B2; AT283567B; FR1470573A; CH505930A

Description

June 17, 1969 5 M T ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March '7, 1966 Sheet 1 of 16 June 17, 1969 R. SCHMIDT ET AL Filed March 7, 1966 Sheet of 16 June 17, 1969 R scHMlDT ETAL SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Sheet 5 of 16 Filed March 7, 1966 FIG. 4

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J1me 1969 R. SCHMIDT ET AL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March '2, 1966 Sheet 4 of 1s FIG. 5 F/G. 6

June 17, 1969 $HM|DT ET AL SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March '7, 1966 Sheet FIG. 7

June 17, 1969 s T ET AL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 6 of 16 FIG. 70

I June 1969 R. SCHMIDT ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 7 of 16 FIG. 77

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June 17, 1969 R. SCHMIDT ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 8 of 16 FIG. 72

June 17, 1969 D-r ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 9 of 1s June 17, 1969 R. SCHMIDT ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7. 1966 Sheet I0 of 16 FIG. 75

June 17, 1969 R m-r ET AL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet I of 16 FIG. 76

June 17, 1969 R. SCHMIDT ET AL 3,449,928.

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 03 of 16 w 2 Q3 Q m w Y June 17, 1969 R. SCHMIDT ET AL SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet 3 of 16 INVENTORS {it A a My 1;. a m, u; r-

June 17, 1969 R. SCHMIDT ETAL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet /4 of 1a June 17, 1969 sc M T ET AL 3,449,928

SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March 7, 1966 Sheet /5 of 1s FIG. 77

June 17, 1969 SELECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES Filed March '7, 1966 R. SCHMIDT ET AL Sheet of 16 United States Patent U.S. Cl. 66-50 20 Claims ABSTRACT OF THE DISCLOSURE Jacks mounted on a needle cylinder are biassed to move from an inoperative position to a working position guided by cam tracks to raise needles. Control members cooperate with the jacks and are individually controlled by a program controlled electromagnet and by cams to move selected jacks to the inoperative position.

The present invention relates to a selector apparatus for a circular knitting machine, and more particularly to selector apparatus for controlling selected cylinder needles of a circular knitting machine to assume at each feeding or knitting station, positions required by a de ired pattern.

The selector apparatus of the invention is preferably provided in a circular knitting machine which has cylinder needles operated by jacks which are respectively aligned with the cylinder needles for moving the same.

The term jack is used herein to refer to any means by which the movement of needles of a knitting machine is influenced.

It is one object of the invention to provide a selector apparatus in a knitting machine by which selected jacks are actuated to cause desired needle movement.

Another object of the invention is to provide selector means by which the selection of needles can be carried out at a very high speed with great accuracy and without errors.

Another object of the invention is to provide, a knitting machine with control elements actuated by electromagnetic selector means and being constructed in such a manner that a selection can be carried out within an extremely short time, while only a small magnetic force is required of the electromagnetic selector means.

With these objects in view, one embodiment of the invention is used in a circular knitting machine which includes a rotary needle cylinder, a cam box surrounding the needle cylinder and having at least one circumferential jack cam track including track portions rising and falling in axial direction; and a series of needles mounted on the needle cylinder for movement in axial direction. In accordance with the invention, a series of jacks registering with the needles is provided. Each jack is mounted on the needle cylinder for movement in axial direction, and also for movement in radial direction between an inoperative position and a working position engaging the jack cam track so as to be moved by the rising and falling track portions to and from an operative position for lifting the corresponding needles.

Selector means are mounted on the cam box for selectively placing jacks in the inoperative or working positions, respectively. Only those needles are lifted by the jacks, whose jacks are selected to be raised in the working position to the operative position engaging the respective needles.

Each jack has one end supported on the needle cylinder for angular movement between the inoperative and the working position, and has a butt located in the jack cam track in the Working position of the jack. A spring biases each jack to move outward in radial direction to the working position in which its butt is located in the jack cam track of the cam box. A series of control elements, preferably straight resilient wires, is mounted on the needle cylinder located outward of the jacks. When a control element is actuated by the selector means, it is moved to an actuated position for moving the respective jack to the inoperative position. The control elements successively pass electromagnetic selector means during rotation of the needle cylinder, and also selector cam tracks. When a control element is attracted by the electromagnetic selector means, it moves along one selector track in a position spaced from the jack so that the same remains in the working position into which it is urged by the biasing spring thereof. It a control element is not selected by the electromagnetic means, it passe upon another selector cam track which presses the resilient control element to the actuated position in which it engages the respective jack and presses the same against the action of its biasing spring to an inoperative position in which its butt is located outside of the jack cam track.

In the preferred embodiment of the invention, the electromagnetic selector means has a selector core which is a permanent magnet. When a winding on the selector core is energized under control of pattern control means at the moment in which it is passed by a control element, the magnetic field produced by the winding extinguishes or compensates the magnetic field produced by the permanent magnetism of the selector core, so that the respective control element is not held by the selector core, and released to move due to its resiliency toward the actuated position for displacing the respective jack.

Preferably, guide cam tracks are provided for guiding the control elements successively into the proximity of the selector core, and a permanent magnet, which is not under the influence of a winding, follows the selector core for holding a selected and attracted control element until the same continues its movement on the selector cam track which holds the respective control element in a position permitting the biasing spring of the corresponding jack to press the same into the working position. The rising and falling cam track portions of the jack cam track follow the selector magnet and the selector cam track means in the direction of rotation of the needle cylinder so that the selected jacks are raised by the rising jack cam track portion to a position engaging the corresponding needles and placing the same on rising needle track portions on which the selected needles are displaced to assume at least the tuck position.

Preferably, shifting means in the form of turnable cams mounted in the cam box are provided which have an operative position for raising selected needles from the tuck position to the highest knit position. The shifting means may be operated by pattern control means, or manually set in the respective knitting and feeding station. A knitting machine to which the present invention is applied may, for example, have twenty four knitting and feeding stations.

The energization of the windings of the electromagnetic selector means at each knitting and feeding station takes place under the control of program control means which determine the knitting pattern.

In the preferred embodiment of the invention, a program tape is provided with as many program tracks as there are knitting stations and electromagnetic selector means in the machine. Each track consists of a sequence of transparent and opaque areas arranged in accordance with the needle operations desired at the respective knitting station. A corresponding series of photodiodes receives the light passing through the pattern tracks, and

3 the impulses produced by the photo diodes are amplified and respectively supplied to the electromagnetic selector means at the knitting stations of the machine.

Preferably, synchronizing signals are produced by an impulse generator under the control of the needles, jacks, or grooves of the needle cylinder and assure that the electro magnetic selector means are energized at the exact moment in which they are passed by a cylinder needle and the corresponding jack and control element.

In accordance with the invention, additional tracks are provided on the pattern tape. One additional track may be used for adjusting the position of the photoelectric sensing means if there is a phase difference between the sensed areas of the pattern tracks, and the passage of cylinder needles past the electromagnetic selector means. Another additional track is preferably entirely transparent, and is sensed to indicate whether the transparent areas of all tracks are sufficiently light permeable to assure proper operation of the photoelectric sensing means. If, for example, the areas have darkened, the voltage of the source of light scanning the pattern tracks is increased so that the lamp provides light of greater intensity, and the photo diodes receive the same amount of light irrespective of the condition of the program tape.

Some of the elements in the new combination of the present invention, are disclosed in the US. Patents No. 3,313,129, No. 3,365,916 and No. 3,292,393.

In the preferred embodiment of the invention, a cylindrical lens transports the program tape, and at the same time is part of a lens system by which a narrow line of light is focused by the cylindrical lens onto the program tape. In order to eliminate a phase diiference between the tracks of the program tape and the position of the jack controlling elements when passing the electromagnetic selector means, the photo diodes are turned by a motor about the axis of the cylindrical lens an angle depending on the phase difference which is determined by a phase comparison device to which synchronizing impulses produced by the needle cylinder, and control impulses produced by an additional track on the pattern tape are supplied. The transparent areas of the additional track are uniformly spaced, for example, a transparent area may be provided for every second pattern track area so that a control impulse is supplied to the phase comparison device for every two synchronizing impulses.

The same elimination of a phase difference can be obtained by interrupting the transmission between the needle cylinder and the transporting means of the program tape. For example, two shafts respectively connected with the needle cylinder and with transporting means for the program tape carry spur gears having opposite helical teeth meshing with a helical spur gear fixedly secured to a common shaft which is axially shiftable and connected by a reduction transmission to a motor. The motor is controlled by a voltage produced by a phase comparison device responding to control signals produced by a photo diode sensing an additional control track on the pattern tape, and by the synchronizing impulses derived from the needle cylinder .to shift the intermediate shaft and to turn the helical gear on the shaft of the transporting means.

By eliminating the phase difference, different pattern tapes can be used on which the transparent and opaque areas are displaced slightly different distances in relation to the transporting perforations.

If the machine is first controlled by a pattern tape to produce a certain pattern, and the pattern tape is replaced by another to produce a different knitting pattern, the control impulses produced by the pattern tracks of the new tape may be phase displaced in relation to the synchronizing impulses produced by an impulse generator under control of the needle cylinder, so that the synchronizing impulses do not coincide at all with the impulses produced by the photo diodes sensing the pattern track. As explained above, this phase difference can be eliminated by adjusting the position of the photoelectric sensing means about the axis of the cylindrical transporting lens or by an automatically adjusted transmission between the needle cylinder and the transporting means for the pattern tape. In the latter case the actual displacement of the shaft carrying the two spur gears with helical teeth, effects adjustment and elimination of the phase difference.

Additional tracks on the pattern tape may also be used for other purposes, for example for producing a lknitting pattern requiring operation of every second needle which may be accomplished by the control track having alternate transparent and opaque areas for controlling the comparison device.

The other additional control track, which is transparent throughout, serves, as explained above, for assuring that irrespective of the prevailing conditions, control signals of desired strength are produced by the photo diodes. The proper response of the photo diodes may be influenced by different factors. For instance, the sensitivity of the photo diodes at different temperatures of the machine may change, which would result in different responses after the machine has been stopped for some time and cooled off, and after the machine has been operated for some time. The scanning lamp may also lose its brightness after extended use. As noted above, the transparent areas of the pattern tape may become less light permeable as the tape ages. Finally, losses of light may occur if the program tape is slightly laterally displaced so that not the entire width of each pattern track is sensed by the photo diode.

By varying the light intensity of the scanning lamp, under the control of an additional control cam track, it is possible to obtain from the photo diodes control impulses of uniform strength.

A knitting machine according to the present invention comprises several novel features which cooperate to result in a Jacquard knitting machine which has unlimited possibilities of pattern variations, while the pattern can be selected and changed by the replacement of a program tape, preferably by means of a cartridge.

The following devices form part of the machine:

(1) An optical sensing device for a pattern tape including photoelectric devices, such as photo diodes.

(2) Control and regulating devices by which the impulses produced by the photo diodes are maintained at a uniform level, and amplifiers for the control impulses.

(3) Selector means including electomagnetic means and selector cams controlled by the control impulses received from the photo diodes and amplifiers so that the electromagnetic selector means are reliably controlled for producing the mechanical motions required for the selection.

(4) Radially movable jacks controlled by control elements actuated by the selector means.

(5) Shifting means in the needle cam tracks for selectively raising needles at the knitting stations to a higher position.

Due to this combination, it is possible to provide electric apparatus which is so small that all electric and electronic elements can be mounted within the base of a circular knitting machine which contains the drive means of the same, and also in other parts of the machine. The novel features of the invention permit the operation of the knitting machine at extremely high speed at which only very short time periods are available for the selection of needles in accordance with the knitting pattern.

A circular rib top knitting machine whose needle cylinder rotates at 18 revolutions per minute, and which has a needle circle diameter of 30 inches and 1,680 cylinder needles, affords the time of 1.8 milliseconds for the selection of a needle. Considering that a time interval must be provided between selections of successive needles, the sensing transmission of impulses and selection by the selector means must be carried out in less than 1 millisecond. Since the novel features of the invention result in a selection time of only 0.5 millisecond, it is possible to increase the number of revolutions of the needle cylinders substantially over the usual 18 revolutions per minute.

Each program tape is located in a cartridge and has a length of about 150 meters. A program tape of this length is capable of producing 8 million control impulses. In order to control pattern wheels, for example, with a number of control impulses of this size in a conventional machine having twenty four knitting stations, twenty four pattern wheels each of which has a diameter of 150 meters would be required which, of course, is impractical. Even knitting machines which are controlled by electromagnetic and mechanical selector means according to the prior art, are incapable of the storage and use of such an enormous number of control signals.

An advantage of the machine of the present invention is that no knowledge of the electronic apparatus is required of the operator, since the selection is automatic. The electronic devices are preferably constructed of transistors since the same permit a more compact construction and have greater mechanical resistance to shock. Parts of the photoelectric sensing device are disclosed in the US. Patent No. 3,317,735.

As explained above, jacks are selected by operation of the selector means. The selected jacks are controlled by a jack cam track to raise the corresponding needles onto a rising needle cam track portion which guides selected needles from the cast-off position to the tuck position, while non-selected needles continue their movement along a horizontal cam track in the cast-off position. A shifting cam is provided which can be placed in a position for forming a further rising track for the selected needles, so that the same are raised from the tuck position to the knit position. Following the shifting cam, the falling cam track of a stitch cam is located for returning the needles from the tuck or knit positions to the cast-off position. When the shifting cam is turned to an inoperative position, the respective needles are guided toward the falling cam track on the shifting cam in the tuck position without reaching the knit position.

This construction permits not only an unlimited selection of the jacks for moving the needles to the tuck position, but also a selection of the needles which are moved from the tuck position to the higher knit position. Shifting cams are provided at each knitting and feeding station of the circular knitting machine, and may be differently set at different knitting stations, entirely independent of the selection of the needles by the jacks under the control of the program controlled selector means.

In accordance with the invention, another shifting cam is provided leading the rising track portion of the needle cam by which the selected needles are raised to the tuck position. The second shifting cam, which leads the firstmentioned shifting cam in the direction of rotation of the needle cylinder, can be shifted to an operative position for guiding all needles out of their non-knit horizontal needle track portion onto the rising needle track portion, irrespective of the jack operation. This shifting cam can be turned to an inoperative position located below the needle cam track, and a corresponding cavity is provided in the cam plate which is attached to the cam 'box.

When the second shifting cam is operative, all needles are guided to the tuck position, and if the first-mentioned shifting cam is also operative, they are guided to the next position, while the selector means may be rendered inoperative.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its means of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary developed view illustrating a segment of a cam box of a circular knitting machine provided with cam tracks according to the invention;

FIG. 2 is a fragmentary axial sectional view taken on line 2-2 in FIG. 1, and illustrating a selector apparatus according to the invention;

FIG. 3 is a fragmentary sectional view taken on line 33 in FIG. 1;

FIG. 4 is a fragmentary axial sectional view taken on line 4-4 in FIG. 1 and illustrating a jack in an inoperative position;

FIG. 5 is a framentary axial sectional view taken on line 44 in FIG. 1 and illustrating a jack in an operative position;

FIG. 6 is a fragmentary axial sectional view taken on lines 6-6 in FIG. 1 and FIG. 15 and illustrating a control element in an actuated position for moving the corresponding jack to the inoperative position;

FIG. 7 is a framentary axial sectional View taken on lines 77 in FIGS. 1 and 15 and illustrating a control element in a tensioned displaced position;

FIG. 8 is a frgamentary axial sectional view taken on lines 8-8 in FIGS. 1 and 15 and illustrating a control element attracted by electromagnet means and another control element released by the electromagnet means;

FIG. 9 is a fragmentary axial sectional view taken on lines 99 in FIG. 1 and FIG. 15, and illustrating a control element in the displaced tensioned position;

FIG. 10 is a fragmentary axial sectional view taken on lines 10-10 in FIGS. 1 and 15;

FIG. 11 is a frgamentary view taken on line 11--11 in FIG. 15, and illustrating electromagnetic selector means;

FIG. 12 is a fragmentary sectional view taken on line 1212 in FIG. 11, as viewed from the right in the direction of the arrow 12 in FIG. 11;

FIG. 13 is a fragmentary sectional view taken on line 1313 in FIG. 11, and on lines 8-8 in FIGS. 1 and 15;

FIG. 14 is a fragmentary sectional view taken on line 1414 in FIG. 11;

FIG. 15 is a horizontal sectional view taken on line 15-15 in FIG. 1 and illustrating selector means according to the invention;

FIG. 16 is a diagram illustrating the electric circuit of pattern control apparatus by which the energization of electromagnetic selector means according to the invention is controlled by a program tape;

FIG. 16a is a fragmentary sectional view illustrating an electromagnetic sensing means controlled by the needle cylinder of the knitting machine;

FIGS. 16b and are diagrams illustrating a circuit for producing rectangular synchronizing impulses;

FIG. 16d is a diagram illustrating an. electric circuit for combining pattern representing impulses produced by photoelectric sensing means with synchronizing impulses shaped by the circuit of FIGS. 16b and 16c;

FIG. 17 is a side elevation illustrating a photoelectric sensing apparatus forming part of the pattern control apparatus of FIG. 16;

FIG. 18 is a plan view of the apparatus of FIG. 17;

FIG. 19 illustrates a detail of the apparatus of FIGS. 17 and 18 on an enlarged scale; and

FIG. 20 is a fragmentary view illustrating a section of a program tape used in the pattern control apparatus illustrated in FIG. 16; and

FIG. 21 is a fragmentary sectional view illustrating a device for adjusting the position of the program tape in relation to the position of the needle cylinder.

Referring now to the drawings, and more particularly to FIGS. 1 and 2, a needle cylinder 2 is rotatable about a vertical axis of rotation, not shown, and has circumfererrtially adjacent peripheral channels 18 extending parallel to each other in axial direction and being separated by walls 4 which are preferably inserted into corresponding grooves 4b of needle cylinder 2. Needles 1 are mounted for axial sliding movement in channels 18 and have butts 1 located and guided in a needle cam track 6 in an annular cam box 90 which surrounds needle cylinder 2. Cam box 90 is divided into as many sectors as there are knitting or feeding stations provided in the machine, and each sector has an upper part T and a lower part T which abut each other in a common plane T extending perpendicular to the axis of the needle cylinder. The lower parts T" are secured by screws 171 to a circular base 182, and the upper parts T are secured to the respective lower parts by screws, not shown, which permit detachment of the upper part of each sector.

Cam plates are secured to the inner surface of each sector part and form circumferential cam tracks with slanted cam track portions rising and falling in axial direction.

The needle cam track 6 has a lower guide face which is formed by the upper edge of a cam plate 100 which is secured by screws 100'. The upper guide face of the needle cam track is partly formed by stitch cam plate 10 having a slanted surface 10', and by another cam plate 9 to which a further cam plate 17 is secured which has a projection forming a rising cam track 7', as best seen in FIG. 1 which shows one sector S of carn box 90.

A jack 3 is slidably mounted in each channel 18 of the needle cylinder 2. The term jack is used herein to define a control member which influences directly or indirectly movements of a needle. In the illustrated embodiment, a jack 3 registers with each cylinder needle 1. Each jack has a lower end portion 3a which is rounded off and slidably abuts a corresponding bearing seat 3b at the end of the respective channel 18. Consequently, each jack 3 is mounted for angular movement between a working position in which its butt 3 is located in a jack cam track 5, and an inoperative position shown in FIG. 4 in which the jack has turned about its lower end 311 against the action of a spring 19 which is secured to each jack, and has a curved portion abutting the bottom 18a of the respective channel 18. Each jack has a projection 3d which is located in close proximity of a resilient control element 2.1 which is shown to be a straight resilient wire secured to a ring 22 surrounding the needle cylinder and secured to the same by screws 23.

Biasing means 19 urge the jacks into the working position shown in FIG. 2, but \when a control element 21 is turned to the position shown in FIG. 6, for example, it engages projection 3d and turns the respective jack in counterclockwise direction to an inoperative position in which butt 3 is located outside of jack cam track 5, and biasing spring 19 is resiliently deformed. As clearly shown in FIG. 2, each jack 3 is aligned with a corresponding needle 1 only in the working position.

Jack cam track 5 is located in the region of the dividing plane T, and has horizontal cam track portions 5h which are located ina plane perpendicular to the axis of the needle cylinder. A rising earn track portion 5, a falling cam track portion 5", and a horizontal high cam track portion 5a are provided between the horizontal cam track portions 5h. When a jack 3 moving in the direction of the arrow P with the needle cylinder while being in the working position is raised by the rising cam track portion 5' to the operative position shown in FIG. 5, the upper end of the jack engages the corresponding needle and raises the same to the higher position shown in FIG. 3 whereupon the falling cam track portion 5" lowers the jack again.

Selector means are provided in the region of cam 127 for placing selected jacks in the working position, and non-selected jacks in the inoperative position in which the respective butts are not located in the rising cam track portion 5', but slide on the outer surface of cam 20, as shown in FIG. 4 so that the respective needles are not engaged and raised by non-selected jacks.

The needle cam track 6 has a cam track 61' extending over the entire circumferential length of each cam box sector in a plane perpendicular to the axis of rotation of needle cylinder 2, so that needles whose butts remain on track 61', remain in the lowest position which corresponds to the cast off position, so that the respective needles cannot catch a thread or form a loop. At a point 7, a rising cam track 7' branches off, and needles whose butts are controlled by track portion 7' are raised to the tuck position. If a shifting cam 11 is in the illustrated position, the needle is further raised to the point 8 at the upper end of shifting cam 11 where the needle is in the knit position. A falling track portion 13 ending in a point 13', and another falling stitch cam portion 10' lower the neeedle to the cast oif position in which the butts are again located on the horizontal track 6i.

Point 7 at which the rising track portion 7 starts in the direction P of needle movement and rotation of the needle cylinder, is located behind the upper end of the rising jack cam track portion 5. Consequently, those jacks which are selected to be moved by cam track 5' in the working position to a higher operative position, engage the corresponding needles 1 before the butts of the same reach point 7, and raise the corresponding needles onto the rising needle track portion 7' for further movement to the tuck position. If shifting cam 11 is in the illustrated position, the respective selected needle is further raised to the knit position, but if shifting cam 11 is turned in counterclockwise direction about a pivot means 12 in the cam box, the respective needle remains in the tuck position and travels along a horizontal path toward stitch cam 10 by which it is lowered to the cast off position.

Shifting cam 11 cooperates with a locking means 14 which is turnable about its pivot 151. Locking means 14 is turnable to the illustrated locking position arresting shifting cam 11 in its operative position, but when locking means 14 is turned in counterclockwise direction to an inoperative position, shifting cam is lowered so that its cam face 11 is parallel to needle track 61' and located slightly above the same so as not to interfere with needle butts 1 traveling along track 6i.

As long as shifting cam 11 is in the illustrated operative position, all needles are raised to the knit position and then lowered by cam tracks 13 and 10' to the cast off position.

Those needles which are not raised by non-selected jacks which are in the inoperative position shown in FIG. 4, pass the sector in the cast off position while the butts thereof are guided along track 6i.

The position of shifting cam 11 can be selected, and may be different or the same in successive cam box sections corresponding to knitting or feeding stations. Shifting earns 11 may be manually set to selected positions at the various knitting stations of the machine, but it is also possible to control shifting earns 11 by pattern control means substantially as described in the US. Patent 3,186,192. The chain line 1a schematically indicates the path of movement of a needle which is raised to the knitting position, and the path of the upper end of a jack which is raised to the operative position is indicated by a chain line 30.

Another shifting cam 15 is mounted for turning movement in the cam box and located in a recess in the outer face of cam plate 100. Shifting cam 15 cooperates with a turnable locking means 16, and can be turned to a position, not illustrated, in which shifting cam 15 forms a rising cam track connecting point 7 with the horizontal track 6i so that all needles are raised by shifting cam 15 to the rising track portion 7 and raised to the tuck position, or to the knit position depending on the position of shifting cam 11. As long as shifting cam 15 is in the operative position connecting track 61' with track 7, it is immaterial whether the corresponding jacks are in the inoperative or working position.

Shifting cam 15 is operated only if no selection of jacks is desired. As noted above, selector means which will be described hereinafter, place the jacks either in the inoperative position of FIG. 4, or in the working position of FIG. 5 so that selected needles are raised, while non