GB2039544A - Circular warp knitting machine - Google Patents

Abstract

A circular warp knitting machine is designed for knitting hosiery pieces and comprises a stationary needle cylinder 1, knitting needles 2, radially movable sinkers 3, two sets of guide needles 4a and 4b, received in grooves of two concentrically arranged annular guide bars 5 and 6, racking mechanisms for racking the guide bars 5 and 6 along the front of the knitting needles 2 and rocking mechanisms for rocking each set of guide needles 4a, 4b between the knitting needles 2. The needle cylinder 1 accommodates a sleeve 14 movable therealong to control movement of the sinkers 3, and a holder 28 movable along the needle cylinder 1 and carrying the knitting needles 2. Sliding frames 80 and 81 of the rocking mechanisms and concentric rotatable casings 82 and 83 carrying the annular guide bars 5 and 6 are coaxial with the needle cylinder 1. Reciprocation of some of the needles can be interrupted while the others continue to reciprocate for knitted curved hosiery portions. <IMAGE>

Description

SPECIFICATION Circular warp knitting machine The invention relates to the knitwear manufacture, and more particularly, to circular warp knitting machines for knitting hosiery pieces.

According to the invention, it is contemplated a circular warp knitting machine comprising: a stationary needle cylinder; knitting needles which are caused to reciprocate vertically and are arranged around the needle cylinder; a mechansim for imparting said vertical motion to the knitting needles; a holder which is movable along the needle cylinder and coupled to said mechanism causing the vertical movement of the knitting needles, the holder being arranged outside the needle cylinder and carrying the knitting needles mounted therein; a main shaft of the machine; radially movable sinkers having their butts received in an annular cam and installed in grooves of a sinker cup which is arranted inside the needle cylinder; a sleeve movable along the needle cylinder, arranged inside the needle cylinder and having at the upper portion thereof an annular cam for butts of the sinkers, the lower part of the sleeve being operatively connected to the main shaft of the machine to impart radial motion to the sinkers; two sets of guide needles having their butts received in annular cams and installed in grooves of two concentrically arranged guide bars; racking mechanisms for racking the annular guide bars together with the guide needles along the front of the knitting needles; rotatable casings concentrically arranged over the needle cylinder, carrying the annular guide bars and operatively connected to the racking mechanisms; rocking mechanisms for rocking each set of the guide needles between the knitting needles; sliding frames of the rocking mechanisms of the guide needles installed over the needle cylinder coaxially therewith and carrying annular cams to receive butts of the guide needles.

This arrangement of the mechanisms in a circular warp knitting machine ensures reliable stitchforming process and stable movement of the needles, sinkers and guide needles thus enabling the maintenance of a constant pre-set speed of the machine and its high output.

According to the invention, the sleeve is installed in a cylindeical guide which is formed by the needle cylinder and a tube secured to the machine bed and supporting a sinker funnel, and the operative connection of the sleeve to the main shaft for rotation relative thereto, links articulated to the sleeve and to the frame and a double-arm lever having one arm which is articulated to the frame by means of a rod and the other arm permanently engaging a member imparting motion to the sinkers which is mounted on the main shaft, all articulation joints of the frame and double-arm lever being adjustable length. This improves stability of sinkers in operation and enlarges the range of adjustment of the sinkers size.

According to the invention, the holder carrying the knitting needles is formed by two concentrically arranged sleeves, the outer sleeve having an annular groove to receive butts of the knitting needles, and the inner sleeve having grooves to receive shanks of the knitting needles.

The invention is characterized in that the holder comprises two longitudinally extending portions, and the mechanism imparting vertical motion to the knitting needles comprises a crank gear, a rotatable frame connected to a crankshaft of the crank gear which is installed on the main shaft of the machine, and legs mounted on the rotatable frame, each leg being coupled to the respective part of the holder by means of a link and a rod which are articulated to one another, the leg associated with one portion of the holder being installed on the rotatable frame by means of a sliding key and having a device for moving it along the rotatable frame.

Owing to an independent drive of each portion of the holder hosiery pieces of any curved shape may be made.

The invention is also characterized in that the device for moving the leg along the rotatable frame comprises a drive shaft which is connected to the main shaft of the machine by means of a gear train and a Geneva mechanism having its drive wheel secured to the drive shaft and a shaft of a driven wheel having a cam controlling the movement of the leg by means of a double-arm lever engaging the cam, a link which is operatively connected to the rotatable frame and a rocking slot hole member having its slider which comprises a pin secured to the leg, the leg being elastically biased against a stop secured to the rotatable frame.

This arrangement of the device enables a very rapid disengagement of a part of the needles.

The invention is further characterized in that the sliding frame of each rocking mechanism of the guide needles is installed in guides of the bed and is articulated by means of a link, an arm and a connecting rod to a motion imparting member of the rocking mechanism of the guide needles installed on a drive shaft thereof, the articulation joints connecting the arm to the bed and to the link being adjustable.

Each rocking mechanism of the guide needles preferably has a device for retatining the guide needles in the grooves of the guide bar, the device for retaining the guide needles in the inner guide bar comprising a spring-biased plate secured to a fixed axle coaxially with the inner annular guide bar and having its edge bearing against a toroidal surface of the annular guide bar, and the device for retaining the guide needles in the outer guide bar comprising two superposed rings embracing the guide bar, each ring having internally a toroidal surface and externally an arm, the arms of both rings being interconnected by springs thereby ensuring an elasting bias of the rings against one another and against the toroidal surface of the outer guide bar.This arrangement ensures reliable retaining of the guide needles against leaving the grooves of their respective guide bars without hampering the racking movement of the guide bars.

The invention is further characterized in that the rotatable casings are installed in the bed guides and are articulated by means of a link to racking mechanisms, each racking mechamism comprising a cam with change cam plates which is installed on a drive shaft, and a spring-biased double-arm lever having a roller at one arm to engage the can and connected with the other arm thereof to the link, the cam being formed by a sleeve integral with a plate to which the change cam plates are adjustably secured, one of the cam plates which has a greater radius of the working surface having a projection and consisting of two portions having radially mating planes thereof which are parallel and extend at an angle to the axis of the drive shaft so that the projection of one portion of the cam plate can be brought in the zone of the projection of the other portion of the cam plate.

The invention will now be described in detail with reference to the accompanying drawings showing a specific embodiment of the invention, in which: Figure 1 schematically shows, in a longitudinal section, the relative arrangement of stitch-forming members of a circular warp knitting machine and a kinematic diagram of the sleeve movement; Figure 2 shows a kinematic diagram for moving knitting needles; Figure 3 shows a kinematic diagram of the racking mechanism in a plan view; Figure 4 is a sectional view taken along the line IV-IB in Figure 3; Figure 5 is a sectional view taken along the line V-V in Figure 3; Figure 6 is a view of a cam plate taken along arrow A in Figure 3 (turned at 90 ); Figure 7 is a kinematic diagram of the rocking mechanism of guide needles;; Figure 8 schematically shows the device retaining guide needles in the outer guide bar in section along the guide needles; Figure 9 shows a portion of the ring of the device shown in Figure 8.

A circular warp knitting machine comprises a stationary needle cylinder 1 (Figure 1), knitting needles 2 which are vertically reciprocated, radially movable sinkers 3, two sets of guide needles 4a and 4b for laying two systems of warp threads on the knitting needles 2 installed in grooves of two concentrically arranged annular guide bars 5 and 6, respectively, a mechanism 7 (Figure 2) for vertically moving the knitting needles, racking mechanisms 8 (Figures 3 through 6) for racking the guide bars 5 and 6 together with the guide needles along the front of the knitting needles 2, rocking mechanisms 9 (Figure 7) for rocking each set of guide needles between the knitting needles 2 and a control drum of a control device of the machine of any known design (not shown).It is understood that, in addition to the above-mentioned mechanisms, the circular warp knitting machine is provided with all necessary devices and mechanisms of known type ensuring the stitch-forming process to occur automatically.

The radially movable sinkers 3 (Figure 1) are cresent-shaped and have their butts 10 received in an annular cam 11. The sinkers 3 are installed in grooves 12 of a sinker cup 13 which is secured to the needle cylinder.

The needle cylinder 1 accommodates a sleeve 14 which is movable therealong, have the annular cam 11 at the upper portion thereof and is operatively connected with its lower portion to a main shaft 15 of the machine for imparting radial motion to the sinkers 3. The sleeve 14 is installed in a cylindrical guide which is formed by the needle cylinder 1 and a tube 16 arranged inside the needle cylinder coaxially therewith and secured to bed 17 of the machine by means of pins 18 passing through longitudinal holes of the sleeve 14. A sinker funnel 19 is secured to the upper portion of the tube 16 and retains the sinkers 3 in the grooves 12 of the sinker cup 13, a hosiery piece which is knit being withdrawn through the funnel 19 and the tube 16.

The operative connection of the sleeve 14 to the main shaft 15 of the machine includes a frame 20 which is rotatably mounted on the main shaft 15, links 21 articulated to the sleeve 14 and to the frame 20, and a double-arm lever 22. One arm of the double-arm lever 22 permanently engages, through a roller 23, a cam 24, that is the member imparting motion to the sinkers 3 and determining the displacement of the sleeve 14 along the needle cylinder.

The cam 24 is installed on the main shaft 15. The other arm of the lever 22 is articulated to the frame 20 by means of a rod 22a. Articulation joints 25 which connect the frame 20 to the links 21 and to the rod 22a, and the rod 22a to the double-arm lever 22, are adjustable. For that purpose, the articulation joints comprise sliders secured by means of screws 26 to the frame 20 and to the double-arm lever 22.

The links 21 and the rod 22a are of adjustable length, and for that purpose, each of them is made of two portions (as shown in Figure 1) interconnected by means of a nut 27.

Installed outside the needle cylinder lisa holder 28 which is movable therealong, connected to the mechanism 7 for vertically moving the knitting needles 2 and carries the knitting needles 2 mounted therein, the holder 28 being movable along a smooth surface 29 of the needle cylinder 1 having at the top thereof an annular projection 30 with grooves 31 for knitting needles.

The holder 28 is formed by two concentrically arranged sleeves 32 and 33 and a pressure ring 34.

The inner sleeve 32 directly abuts against the smooth surface 29 of the needle cylinder 1, and the outer sleeve 33 embraces the inner sleeve 32 and has internally an annular groove to receive butts 35 of the knitting needles 2. The inner sleeve 32 has on its side facing the outer sleeve 33 grooves 36 to receive shanks 37 of the knitting needles 2.

The pressure ring 34 is secured to the end face of the outer sleeve 33 by screws 38 and is designed for retaining the knitting needles 2 in the grooves 36.

The holder 28 (Figure 2) is installed on rods 39 and 40 of the mechanism 7 for moving the knitting needles, and the holder 28 may be made of two longitudinally extending portions 41 and 42 so that one of the parts max be disengaged if necessary.

The portion 41 of the holder is installed on the rod 39, and the portion 42 of the holder is installed on the rod 40, the rods 39 and 40 being connected, by means of links 43 and 44, respectively, to legs 45 and 46 of the mechanism 7 for moving the knitting needles.

The mechanism 7 for moving the knitting needles comprises; a crank gear consisting of a crankshaft 47 mounted on the main shaft 15 of the machine and a connecting rod 48; a rotatable frame 49 connected to the crankshaft 47; the legs 45 and 46 installed on the rotatable frame 49.

The rotatable frame 49 is mounted with the ends thereof on the main shaft 15 by means of bushings and is articulated to the connecting rod 48 by means of a link 51 and an arm 50 mounted on the bed, the bushings being rotatable on the main shaft 15.

The leg 45 of the portion 41 of the holder is installed on the rotatable frame 49 by means of a sliding key 52 and has a device for moving the leg 45 along the frame 49. The device 53 comprises a drive shaft 54; a Geneva mechanism comprising a drive wheel 55 secured to the drive shaft 54 and a driven wheel 56 secured to a shaft 57 having a cam 58; a rocking slot hole member 59 and a link 60.

The drive shaft 54 is connected by means of a gear train 61 to the main shaft 15 of the machine.

The cam 58 is designed for controlling the displacement of the leg 45 by means of a double-arm lever 62 which engages, through a roller 63, the cam 58 and, through a roller 64, the link 60, the link 60 being operatively connected to the rotatable frame 49 by means of a double-arm lever 65 and a link 66.

A slider of the rocking slot hole member 59 comprises a pin 67 and is secured to the leg 45, the leg 45 being biased by a spring 68 against a stop 69 secured to the frame 49 by a screw 70.

The rocking slot hole member 59 has a pin 71 engageable with a stop 72 of the link 60, the link 60 being permanently biased by a spring 73 against the roller 64.

The leg 46 of the portion 42 of the holder is secured to the frame 49 by a screw 74, the screws 74 and 70 being designed for adjusting the position of the leg 46 and the stop 69 along the lateral sides of the frame 49 so as to vary the amount of vertical displacement of the portions 41 and 42 of the holder.

The links 43 and 44 are of adjustable length, that is each link consists of two portions interconnected by means of a nut 75 so as to adjust the relative position of the two portions 41 and 42 of the holder.

The double-arm lever 62 is connected to a control drum 78 of the control device of the machine having a strap 79 for controlling the device 53 by means of a rope 76 and a double-arm lever 77.

Mounted over the needle cylinder 1 (Figure 1) coaxially therewith there are sliding frames 80 and 81 of the rocking mechanisms 9 of the guide needles 4a and 4b, respectively, and concentrically arranged rotatable casings 82 and 83 carrying the guide bars 5 and 6, respectively, and operatively connected to the racking mechanisms 8.

To simplify the description, the rocking mechanisms 9 and the rocking mechanisms 8 are only shown for the guide needles 4b of the inner guide bar 6.

For each rocking mechanism of the guide needles, annular cams 84 and 85 are secured to the sliding frames 80 and 81, respectively, to receive butts of the guide needles 4a and 4b.

The sliding frame 81 (Figure 7) is installed in guides 86 of the bed and is articulated by means of a link 87, an arm 88 and a connecting rod 89 to a motion imparting member ofthe rocking mechanism 9 of the guide needles - an eccentric 90. An eccentric 90 is installed on a drive shaft 92 by means of a key 91. Articulation joints B and C which connect the arm 88 to an upright 93 of the bed and to the link 87, respectively, have sleeves 94 and 95 secured to the arm 88 by screws 96 and 97, respectively, for their adjustment.

Each rocking mechanism 9 of the guide needles has a device for retaining the guide needles in grooves of the annular guide bar. Thus, for the inner annular guide bar 6 this device comprises a springbiased plate 98 which is secured to a fixed axle 99 coaxially with the inner annular guide bar 6. The plate 98 bears with the edge thereof against a toroidal surface of the annular guide bar 6.

The plate 98 is secured to the axle 99 by a screw 100 through a spring 101.

For the other guide bar 5 (Figure 8), the device for retaining the guide needles 4a comprises two superposed rings 102 and 103 (Figure 9) embracing the guide bar 5 (Figure 8) and each ring 102, 103 has internally a toroidal surface 104 and externally arms 105, the arms 105 of both rings 102,103 being interconnected by springs 106 so as to ensure an elastic bias of the rings 102 and 103 against one another and against the toroidal surface of the guide bar 5.

The rotatable casing 83 (Figure 1) carrying the inner guide bar 6 is installed in a guide which is formed by a plate 107 of the bed and an end plate 108 and has a projection 109, and the rotatable casing 82 carrying the outer guide bar 5 is installed in a guide formed bythe plate 107 of the bed and a ring 110 and has a projection 111.

The rotatable casing 83 with the projection 109 is articulated by means of a link 112 (Figures 3 and 7) to the racking mechanism 8 of the inner guide bar.

Each racking mechanism 8 (Figure 3) comprises a cam 113 which is installed in a drive shaft 114 (Figure 4) and a spring-biased double-arm lever 115 (Figure 3) having a roller 116 at one arm thereof for engaging the cam 113, the other arm of the lever being connected to the link 112.

The cam 113 isformed by a sleeve 117 (Figure 4) which is integral with a plate 118 to which are adjustably secured change cam plates 119, 120 (Figure 3), 121. For that purpose, the change cam plates have slot holes 122 with screws 123 for securing the change cam plates 120 and 121 and screws 124 and 124a for securing the cam plate 119.

The cam plate 119 has a radius of the working surface which is greater than the radius of the cam plates 120 and 121 and has a projection 125 (Figure 4). The cam plate 119 is made of two portions 1 19a 11 9b (Figure 3) which are so arranged that their radially mating surfaces 126 (Figure 6) are parallel and extend at an angle to the axis of the drive shaft 114, whereby the projection 125 of one portion 119a of the cam plate can be brought in the zone of the projection of the other portion 119b of the cam plate.

The portions of the cam plate 119 have enlarged holes 127 in the zone of the screws 1 24a (Figures 3 and 5).

The projection 111 (Figures 1 through 4) of the rotatable casing 82 is similarly connected to the racking mechanidm 8 of the outer guide bar 5. For a compact arrangement of the racking mechanisms 8 of the guide bras 5 and 6, the sleeve 117 (Figure 5) is installed on a sleeve 128 and is secured thereto by a lock screw 129, and the sleeve 128 is installed on the drive shaft 114 by means of a sliding key 130.

The circular warp knitting machine according to the invention functions in the following manner.

The knitting needles 2 (Figures 1 and 2) are caused to reciprocate vertically by the main shaft 15. The eccentric 47 (Figure 2) of the shaft 15 causes oscillations of the rotatable frame 49 through the connecting rod 48, arm 50 and link 51 so that one side of the frame imparts motion through the leg 46 and link 44 to the rod 40 carrying the portion 42 of the holder 28 with the knitting needles, and the other side of the frame 49 imparts motion through the leg 45 and link 43 to the rod 39 carrying the portion 41 of the holder 28 with the knitting needles 2.

When stitches are formed at all knitting needles 2 in making a hosiery piece, both portions 41 and 42 of the holder 28 are caused to move by the same amount. In this operation mode the leg 45 is fixed relative to the rotatable frame 49 since the spring 68 urges it against the stop 69. The slider 67 fixed to the leg 45 moves within the rocking slot hole member 59.

The rotatable frame 49 permanently imparts motion to the link 60 with the stop 72 through the link 66 and the double-arm lever 65. When both portions 41 and 42 of the holder 28 operate identically, the link 60 is urged by the spring 73 against the roller 64 installed at the end of the double-arm lever 62. The lever 62 with the rope 76 and arm 77 bearing against the strap 79 of the control drum 78 of the control device of the machine is fixed in such a manner that the roller 64 holds the link in the lower position. The projection 72 does not engage the pin 71 and moves therebelow, and the roller 63 of the lever 62 is at the level of the lobes of the cam 58 without engaging them.

The cam 58 receives at regular intervals rotary pulses from the uniformly rotating main shaft 15 through the geartrain 61, drive shaft 54, Geneva mechanism 55, 56 and shaft 57.

To switch the machine for making a curved hosiery piece, a part, e.g. the part 41 of the holder 28 with the knitting needles 2 is disengaged, and the part 42 of the holder 28 continues to move as before.

For switching over, the control drum 78 of the control device of the machine is caused to rotate, the arm 77 is disengaged from the strap 79 and releases the rope 76 and the double-arm lever 62. At this moment a lobe of the cam 58 is opposite the roller 63. The spring 73 acts, through the link 60, on the roller 64 and urges the roller 63 against the cam 58 through the double-arm lever 62. Subsequently, during operation, when a depression of the cam 58 is opposite the roller 63, the lever 62 releases the link 60 and the spring 73 lifts it, the projection 72 engages the pin 71, and the double-arm lever 62 turns so that the roller 63 is received in the depression of the cam 58. When the rotatable frame 49 moves up, the link 60 acts with the projection 72 thereof on the pin 71 to turn the rocking slot hole member 59 towards the main shaft 15.The rocking slot hole member 59 acts on the slider 67 to move the leg 45 along the sliding key 52 of the rotatable frame 49 toward the main shaft 15. The portion 41 of the holder 28 with its knitting needles 2 is not lifted, the needles do not receive threads and do not form new stitches. When the rotatable frame 49 moves down, the link 60 moves away from the main shaft 15 to release the rocking slot hole member 59 and the slider 67 with the leg 45, and the spring 68 causes them to move in the same direction up to the stop 69. The portion 42 of the holder 28 is not disengaged, and upon any oscillation of the frame 49 threads are laid on its warp threads and an incomplete course is made. The number of incomplete courses depends on the time during which the depression of the cam 58 is opposite the roller 63.

When the Geneva mechanism 55, 56 causes rotation of the cam 58 through the shaft 57, a lobe of the cam 58 gets opposite the roller 63 so as to turn the lever 62, and the roller 64 causes the link 60 to move down. The projection 72 of the link is thus disengaged from the pin 71, and the portion 41 of the holder 28 starts moving identically with the portion 42, so that complete annular courses are made at all needles of the cylinder. The number of complete annular courses depends on the time during which the lobe of the cam 58 is opposite the roller 63.

Upon every next passage of one depression and one lobe of the cam 58 by the roller, the abovedescribed cycle of making incomplete and complete courses is repeated.

After the curved portion of a hosiery piece is knit, the machine is switched for making the cylindrical portion, and for that purpose the control drum 78 of the control device of the machine is caused to rotate.

The strap 79 engages the arm 77 to turn it, and the rope 76 acts on the lever 62 so that the roller 64 will fix the link 60 in the lower inoperative position, while the roller 63 is disengaged from the cam 58. The control drum 78 is caused to turn for making the curved portion of a hosiery piece and for switching over for making the cylindrical portion at a moment when a lobe of the cam 58 is opposite the roller 63.

In knitting both curved hosiery piece and cylindrical pieces the sinkers 3 (Figure 1) and the guide bars 4a and 4b continue to move.

The radial movement of the sinker 3 in the grooves of the sinker cup 13 is caused by the main shaft 15 by means of the cam 24, roller 23, double-arm lever 22, rod 22a, rotatable frame 20, links 21, sleeve 14 and annular cam 11 which receives the butts 10 of the sinkers 3. The sleeve 14 moves steadily within the cylindrical guide formed by the inner surface of the cylinder 1 and the outer surface of the tube 16.

Radial movement of the guide needles 4a in the grooves of the outer guide bar 5 and of the guide needles 4b in the grooves of the inner guide bar 6 is caused by the drive shaft 92 (Figure 7) by means of identical rocking mechanisms 9.

Rotary motion is transmitted from the shaft 92 through the key 91 to the eccentric 90. The motion is transmitted from the eccentric 90 through the con necting rod 89, arm 88, link 87 and sliding frame 81 to the annular cam 85 which acts on the butts of the guide needles 4b to impart radial rocking movement thereto in the grooves of the guide bar 6. The guide needles 4b are retained within the grooves of the guide bar 6 by the plate 98 which is urged against the toroidal surface of the guide bar 6 by the screw 100 through the spring 101 which prevents inadvertent loosening of the screw 100 during the rocking movement of the guide bar along the front of the knitting needles.

The guide needles 4a are retained within the grooves of the outer guide bar 5 (Figure 8) by means of the two rings 102 and 103 which are urged with their inner toroidal surfaces 104 against the outer surface of the guide bar 5 by means of the spring 106.

The racking motion along the front of the knitting needles 2 is imparted to the guide needles 4b (Figure 1) and to the guide bar 6 which is secured to the rotatable casing 83. The rotatable casing 83 with the guide bar 6 is caused to move by the racking mechanism 8 (Figure 3) in which the drive shaft 114 (Figure 4) permanently imparts rotary motion to the cam 113 (Figure 3). The cam 113 imparts motion through the roller 116 to the spring-biased lever 115, and the latter transmits this motion to the rotatable casing 83 through the 1 link 112 and the projection 109.

Similarly the identical racking mechanism 8 ensures the movement of the guide needles 4a with the guide bar 5 and the rotatable casing 82 carrying it.

The movement of all stitch-forming members knitting needles 2, sinkers 3, guide bars 4a and 4b - is adjustable.

The stroke of the sinkers 3 is adjusted by displacing the articulation joints 25 along the sides of the frame 20 and along the lever 22, with subsequent locking by the screw 26.

The path of movement of the guide needles may be displaced with respect to the front of the knitting needles 2 by adjusting the length of the rod 22a and the link 21 using the nuts 27.

The stroke of the knitting needles 2 (Figure 2) secured to the part 42 of the holder 28 is adjusted by displacing the leg 46 along the side of the frame 49 with subsequent locking by the screw 74. The stroke of the knitting needles 2 secured to the part 41 of the holder 28 is adjusted by displacing the stop 69 along the side of the frame 49, with subsequent locking by the screw 70. The path of movement of the knitting needles may be vertically adjusted by changing the length of the links 43 and 44 by means of the nuts 75.

The radial rocking stroke of the guide needles 4b (Figure 7) may be adjusted by relative displacement of the articulation joints C and B and arm 88 within the bushings 95 and 94, with subsequent locking by the screws 97 and 96, respectively, on the arm 88.

The rocking path of the guide needles is changed by adjusting the length of the connecting rod 89 which consists of two parts threaded together. The stroke adjustment is also provided for the guide needles 4a (not shown in Figures 1 and 7).

Relative position of the guide needles along the front of the knitting needles 2 (Figure 3) is changed by changing the length of the link 112, and the timing of the racking motions is adjusted by displacing the change cam plates 119,120 and 121 with respect to the sleeve 117, with subsequent locking by the screws 124a and 124. The cam plate 119 has an individual adjustmentforeach portion 119a and 11 9b thereof.

Claims (9)

1. A circular knitting machine comprising a stationary needle cylinder, knitting needles arranged around the needle cylinder and carried by a holder located outside the needle cylinder, drive means for moving the holder to reciprocate the knitting needles parallel to the needle cylinder axis, a sinker cup arranged inside the needle cylinder, sinkers received in grooves of the sinker cup and coupled to annular cam means provided on a sleeve located inside the needle cylinder and movable along the axis thereof, the opposite end of the shaft being coupled to a main shaft for moving the sleeve and cam means to impart radial motion to the sinkers, two sets of guide needles received in grooves of respective concentric annular guide bars carried by rotatable casings coaxial with the needle cylinder, racking mechanisms for oscillating the casings and annular guide bars about the axis thereof for reciprocating the guide needles along the front of the knitting needles, and rocking means for rocking each set of guide needles between the knitting needles the rocking means including annular cams coupled to the guide needles and coaxial with the needle cylinder and means for displacing the annular cams in the axial direction.

2. A machine as claimed in Claim 1, wherein the sleeve is located between the needle cylinder and a stationary inner tube supporting a sinker funnel, and the sleeve is coupled to the main shaft of the machine by a frame rotatably mounted on the main shaft, links articulated to the sleeve and to the frame, and a double-arm lever having one arm articulated to the frame by a link rod and the other arm coupled to a driving member mounted on the main shaft, the articulation joints between the frame and doublearm lever being adjustable and the links and link rod being adjustable in length.

3. A machine as claimed in Claim 1 or 2, wherein the holder comprises concentric inner and outer sleeves, the outer sleeve having an annular groove receiving lateral projections of the knitting needles, and the inner sleeve being grooved to receive shanks of the knitting needles.

4. A machine as claimed in Claim 1,2 or 3, wherein the holder is divided into two longitudinally arcuate portions, and the drive means for the holder includes a crank gear, a rotatable frame connected to a crankshaft of the crank gear the holder portions each being coupled to the frame by articulated link means, the link means associated with one portion of the holder being connected to the sliding connection, and being operableto actuate the sliding connection whereby the said one holder portion remains stationary during oscillation of the frame.

5. A machine as claimed in Claim 4, wherein said means for actuating the sliding connection comprises a shaft arranged to be driven by the main shaft through a Geneva mechanism, a cam carried on the shaft, a double-arm lever having one arm engaging the cam, a link connected to the rotatable frame to be reciprocated longitudinally in response to oscillation of the frame, a slotted member carried by the link, and a pin engaged in the slot of the slotted member and connected to the link means of the said one holder portion, the link means being biased towards a stop to the frame.

6. A machine as claimed in any one of Claims 1 to 5, wherein annular cams are carried by sliding frames, each said frame is guided for movement axiaily of the needle cylinder and is connected to a drive member by a link, an arm and a connecting rod, and articulation joints connecting the arm to the machine bed and to the link being adjustable.

7. A machine as claimed in Claim 6, wherein a device is provided for retaining the guide needles in the grooves of each of the guide bars, the device for retaining the guide needles in the inner guide bar comprising a plate secured to a fixed axle coaxial with the inner guide bar and spring biased to urge it edge against a toroidal surface of the guide bar, and the device for retaining the guide needles in the outer guide bar comprising two superposed rings surrounding the guide bar, each ring having an internal toroidal surface the rings being interconnected by springs which bias the rings towards one another and against a toroidal surface of the outer guide bar.

8. A machine as claimed in any one of claims 1 to 7, wherein each racking mechanism comprises a cam with adjustable cam plates, and a spring-biased double-arm lever having a roller on one arm urged by the spring bias to engage the cam, the other arm of the lever being connected to a link which is connected to the rotatable casing, the cam being formed by a sleeve which is integral with a plate and to which the adjustable cam plates are adjustably secured, one of the cam plates having a greater radius consisting of two portions with confronting parallel edges inclined at radial mating plane parallel and an angle to the cam axis so that the projection of one portion of the cam plate can be brought in the zone of the projection of the other portion of the cam plate.

9. Acircularwarp knitting machine substantially as herein described with references to, and as shown in the accompanying drawings.