US3392551A

US3392551A - Pneumatic take-up or tensioning device for circular knitting machines

Info

Publication number: US3392551A
Application number: US375074A
Authority: US
Inventors: Tenconi Riccardo
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-06-22
Filing date: 1964-06-15
Publication date: 1968-07-16
Anticipated expiration: 1985-07-16
Also published as: DE1785634B2; DE1785634A1; ES301227A1; GB1033232A; DE1585197C3; DE1585197A1; DE1585197B2; NL6406987A; BE649570A

Abstract

1, 033, 232. Knitting-machines. M. S. MORETTA. [trading as MORETTA OFFICINE MECCANICHE FABRICA SPECIALIZZATA MACCHINE PER CALZE DI SESSA MARCELLA.] June 19, 1964 [June 22, 1963], No. 25358/64. Heading D1C. A pneumatic tensioning device for a circular knitting machine comprises means to produce an airflow in an upward direction which pulls the tubular knitted fabric directly into an external tube 18, without allowing the fabric to enter the needle cylinder, the external tube 18 being arranged eccentrically with respect to the axis of the needle cylinder. In Fig. 3 the airflow is created by a fan 23 and a tube 19 mounted within the needle cylinder. In a modification Fig. 5 (not shown) the airflow is produced by connecting the tube 18 directly to an external source of suction or low pressure, a trap being provided to remove the articles produced from the intermediate piping before reacting the suction fan.

Description

July 16. 1968 R. TEN co 3,392,551

PNEUMATIC TAKE-UP OB TENSI ING DEVICE FOR CIRCULAR KNITTING MACHINES Filed June 15, 1964 5 Sheets-Sheet 1 I NV EN TOR. Reece/30 7Zn/COM/ July 16. 1968 R TENCQN] 3,392,551

PNEUMATIC TAKE-UP OR TENSIONING DEVICE FOR CIRCULAR KNITTING MACHINES Filed June 15, 1964 5 Sheets-Sheet 2 INVENTOR. ?/ec 400a '7 2-: a arr July 16. 1968 R. TENCONI 3,392,551

PNEUMATIC TAKE-UP OR TENSIONING DEVICE FOR CIRCULAR KNITTING MACHINES Filed June 15, 1964 5 Sheets-Sheet 5 INVENTOR.

July 16. 1968 PNEUMATIC TAKE-UP OR TENSIONING DEVICE FOR Filed June 15, 1964 CIRCULAR KNITTING MACHINES 5 Sheets-Sheet 4 h/ #7 F 4a INVENTUR. ?mc/7/eaa 776M001!!! July 16. 1968 R. TENCONI PNEUMATIC TAKE-UP OR TENSIONING DEVICE FOR CIRCULAR KNITTING MACHINES Filed June 15, 1964 5 Sheets-Sheet 5 m v T M w 7 e 3 V m m 2 o I 4 w 4 C e Y B United States Patent 13 Claims (Cl. 66-149) ABSTRACT OF THE DISCLOSURE A circular knitting machine having a cylinder bearing an annular series of needles and sinkers cooperating with the needles to form the stitches of a circular knit fabric adjacent one end of the cylinder, is provided with a pneumatic tensioning device to produce a flow of air from the interior to the exterior of the needle cylinder in an axial direction to tension the fabric as it is knit and to pull it out of the needle cylinder at the end at which the stitches are formed. This generally results in the circular knit fabric being tensioned upwardly out of the upper end of the needle cylinder so that the fabric is everted immediately after the formation of the stitches.

This invention relates generally to circular knitting machines of the kind used for the manufacture of hosiery, and is particularly directed to a pneumatic take-up or tensioning device for such machines.

Oircular knitting machines presently employed for the manufacture of hosiery have a vertically arranged, rotatable cylin-der bearing an annular series of needles, and a sinker ring extending around the upper end of the needle cylinder and carrying cam actuated sinkers which cooperate with the needles to form the stitches of a circular or tubular knit fabric adjacent the upper end of the needle cylinder. As the knit fabric is formed, a take-up or tensioning device draws the same downwardly through the needle cylinder so as to maintain a constant tension on the fabric, thereby to achieve uniform knitting thereof. The existing take-up or tensioning devices which are pneumatic, that is, which rely on a flow or stream of air for tensioning the fabric as it is knit, all pass the flow of air longitudinally through the needle cylinder in the downward direction, that is, in the direction from the head or end of the needle cylinder where the stitches are formed toward the opposite end of the needle cylinder. The flow of air downwardly through the needle cylinder may be produced by a source of air under pressure, but is usually produced by a source of low pressure or vacuum. In either case, the circular knitted fabric progressively develops inside the needle cylinder or in a stationary or rotated tube extending axially downward from within the cylinder, and the completed stocking is conveyed out of the bottom of the needle cylinder and into a conduit which carries the same to a connecting chamber. In the first pneumatic tensioning devices, the head or upper end of the needle cylinder was located at a suflicient height so that the stocking being knit therein and tensioned downwardly by the air flow could hang straight within the needle cylinder and its tubular extension, even when the stocking had been knitted to its full length. This required a substantial increase in the height of the machine and particularly of the level of the head at which knitting is being effected, thereby rendering inconvenient the inspection and servicing of the machine. In order to reduce the height of a circular knitting machine provided with a pneumatic tensioning or take-up device, it has been proposed to position a perforated basket or shelf below the needle cylinder and through which the stream of air passes so that the downwardly tensioned stocking is progressively deposited in the perforated basket as knitting of the stocking proceeds. Although the foregoing arrangement makes it possible to reduce the overall height of the machine and to dispose the collecting chamber for the finished stocking directly under the needle cylinder, it is necessary that the perforated basket be rotated with the needle cylinder in order to avoid twisting of the stocking during its form-ation.

In all of the existing circular knitting machines for the production of hosiery, whether such machines are provided with pneumatic tensioning devices, as described above, or with mechanical take-up or tensioning devices, the completed stockings leave the knitting machine in straight condition, that is, with the right side of the knitted fabric facing outwardly. However, it is necessary that the subsequent step in the manufacture of the hosiery, specifically, the step of sewing, be performed on the wrong side, that is, with the stocking everted or turned inside'out. Accordingly, it has been proposed to provide circular knitting machines with pneumatic devices for tensioning the stocking as it is knitted, and further for automatically everting the completed stocking at the time of the press-off cycle thereby to condition the completed stock-ing for the subsequent sewing step. Although pneumatic tensioning and everting devices have now been perfected so as to be capable of the necessary consistent or reliable operation, such devices are relatively complicated and delicate in that they require the use of distributor valves controlled in accordance with the operation of the knitting machine for selecting the part of the air flow through several conduits. Further, where the air flow for tensioning the stocking, or for successively tensioning and then everting the completed stocking, is created by connection to a source of suction or vacuum, as distinguished from a source of air under pressure, it is necessary to use relatively large centrifugal blowers for that purpose.

Accordingly, it is an object of this invention to provide a pneumatic tensioning or take-up device for circular hosiery knitting machines, which device is simpler and more compact than the devices previously proposed for the stated purpose.

Another object is to provide a pneumatic tensioning device that permits the construction of the associated circular knitting machine with its head, at which the sinkers cooperate with the needles to form stitches, being relatively low so as to facilitate inspection of the fabric being knitted and servicing of the machine.

A further object is to provide a pneumatic tensioning device for circular knitting machines which causes the circular knitted fabric to be progressively developed with the right side of the knitted fabric facing inwardly so that, upon completion of a stocking, there is no need to evert the same prior to the next sewing step.

In accordance with an aspect of this invention, a circular knitting machine having a cylinder bearing an annular series of needles and sinkers cooperating with the needles to form the stitches of a circular knit fabric adjacent one end of the cylinder is provided with a pneumatic tensioning device comprising means operative to produce a flow of air from the interior of the needle cylinder to the exterior thereof generally in the axial direction extending toward said one end of the cylinder from the other end thereof, whereby the flow of air is adapted to tension the fabric as it is knit and to pull the knit fabric out of the needle cylinder at the end of the latter at which the stitches are formed. Where the sinkers cooperate with the needles to form the stitches of a circular knit fabric adjacent the upper end of a vertical needle cylinder, as is the usual practice, the foregoing arrangement in accordance with this invention results in the circular knit fabric being tensioned upwardly out of the upper end of the needle cylinder. Thus, there is no longer any need to provide a distance from the head or upper end of the needle cylinder to the ground or floor that is greater than the length of the completed stocking and the head of the knitting machine can be positioned for convenient inspection and servicing of the machine. Further, by reason of the fact that the circular knitted fabric is tensioned upwardly out of the upper end of the needle cylinder at which the sinkers and needles cooperate to form the stitches of the fabric, such fabric is everted, that is, disposed with its right side facing inwardly, immediately after the formation of the stitches, so that there is no need to evert the completed stocking prior to the subsequent sewing step. Accordingly, the mechanisms and time previously required for everting the completed stocking are fully eliminated.

The above, and other objects, features and advantages of the invention, will be apparent in the following detailed description of illustrative embodiments thereof which is to be read in connection with the accompanying drawings, forming a art hereof, and wherein:

FIG. 1 is a diagrammatic vertical sectional view of a circular hosiery knitting machine provided with a pneumatic tensioning device in accordance with one embodiment of this invention, and as viewed along the line II on FIG. 2;

FIG. 2 is a diagrammatic top plan view of the knitting machine and pneumatic tensioning device of FIG. 1;

FIG. 3 is a diagrammatic view illustrating the operation of the pneumatic tensioning device of FIGS. 1 and 2 at an early stage in the production of a stocking;

FIG. 4 is a diagrammatic view similar to a portion of FIG. 3, but illustrating a later stage in the production of the stocking;

FIG. 5 is a diagrammatic vertical sectional view illustrating a pneumatic tensioning device in accordance with another embodiment of this invention as applied to a circular knitting machine of the type commonly used for the production of hosiery with a turned welt; and

FIG. 6 is a diagrammatic view similar to that of FIG. 3, but illustrating a pneumatic tensioning device in accordance with still another embodiment of this invention.

Referring to the drawings in detail, it will be seen that several illustrative embodiments of pneumatic tensioning devices in accordance with this invention are there shown in association with conventional circular knitting machines of types commonly employed for the manufacture of hosiery or stockings. In the drawings, only those parts of the circular knitting machines have been shown that are essential for understanding the present invention, and it is to be understood that the knitting machines are additionally provided with any and all components or assemblies that are usually included therein in accordance with modern knitting machine technology.

Referring to FIG. 1, it will be seen that the circular knitting machine, as there illustrated, generally comprises a framework 1 and a needle cylinder 2 carried by a supporting tube 3 which is rotatably mounted in the framework 1. A rotated drive shaft 4 is also mounted in framework 1 and carries a gear 5 meshing with a gear 6 formed on the supporting tube 3 for effecting rotation of the needle cylinder 2. The needle cylinder 2 is shown rotatable about a vertical axis and its outer surface is formed with axial slots 7 spaced apart circumferentially around the needle cylinder and slidably receiving needles 8. The usual sinker ring 9 is secured to the upper end of cylinder 2 and carries cam actuated sinkers 10 which cooperate with the needles 8 in the known manner to form the stitches of a circular knit fabric. An upright 11 is secured to the framework 1 and, at its upper end, carries a pin 12 on which an arm 13 is pivotally mounted for upward swinging movement from its operative position illustrated on FIG. I. The arm 13 has a slot 14 therein accommodating thread or yarn guides 15 which are rockable on a pivot 16 and constitute a feeding station at which yarns are selectively fed to the needles 8 for knitting by the cooperative action of the latter with the sinkers 10. A cover or dial cap 17 depends from the free end of arm 13 and, in the lowered or operative position of the latter, the cover 17 substantially closes the upper end of needle cylinder 2 and is disposed immediately above the level of the sinking plane of sinkers 10.

Insofar as described above, the knitting machine may be considered conventional. In accordance with the present invention, the cover 17 has an aperture 17a (FIG. 2) at one side, and a suitably mounted fixed tube 18 extends upwardly from needle cylinder 2, and has its lower end located within the aperture 17a. The diameter of tube 18 is substantially smaller than the inner diameter of needle cylinder 2, and the lower end or inlet mouth of tube 18 is located approximately at the plane of sinking of sinkers 10.

In order to provide an upward flow of air within the tube 18, the embodiment of the invention illustrated in FIGS. 1 to 4, inclusive, further has a fixed tube 19 extending generally in the axial direction through the interior of needle cylinder 2 and being suitably secured to the framework 1, as by welding to a bracket 20 on the framework (FIG. l). Tube 19 is in axial alignment with the lower end portion of tube 18, and the upper end of tube 19 is tapered, as shown, to form a nozzle registering with, and being spaced radially from the inlet mouth or lower end of tube 18. A circular plate 21 has an eccentrically located aperture receiving the upper tapered end or nozzle of tube 19 and is secured to the latter, as by welding, so that the plate 21 is fixedly located within needle cylinder 2 at a level below cover 17 so as to define a space 22 therebetween in which the knitting occurs.

As shown particularly on FIG. 3, the lower end of tube 19 is connected to the outlet of a centrifugal blower or fan 23 so that, when the latter is operated, air under pressure from the blower causes an upward air flow through the tube 19, as indicated by the arrow 24. Such upward air flow issues from the tapered upper end or nozzle of tube 19 into the registered lower end of tube 18 and simultaneously induces a relatively low pressure or suction within the space 22 so that air enters around the periphery of the space 22 and is drawn through the latter to enter the tube 18 at the annular clearance between the lower end of tube 18 and the nozzle or tapered upper end of tube 19. Thus, there is created, both in the space 22 and within the tube 18, air flows indicated by the arrows 26 (FIG. 1) which serve to tension the tubular fabric knitted by the cooperative action of the needles 8 and sinkers 10 and to draw such fabric into the mouth of tube 18.

As is shown on FIG. 3, which illustrates the operation of the tensioning device at the beginning of the formation of the border of a stocking, the knitted fabric 25 rotating with the needles 8 and sinkers 10 about the axis of cylinder 2, is sucked immediately after its formation in the space 22 by the streams of air passing through space 22 toward the bottom end or mouth of tube 18 so that the fabric cannot descend within the needle cylinder 2 as in knitting machines with conventional tensioning or take-up devices. Further, the movement of the knitted fabric 25 downwardly within the needle cylinder 2 is prevented by the circular plate 21 which defines the bottom wall of space 22. During the initial formation of the tubular fabric 25, only a portion of the margin thereof enters the lower end of the tube 18, while the remainder of the margin of the fabric remains within the space 22 (FIG. 3). Of course, the portion of the margin entering the tube 18 changes its position continuously, as the tubular fabric rotates with the needles and sinkers, while the tube 18 and the cover 17 and circular plate 21 defining space 22 are stationary. As the knitting of the tubular fabric 25 progresses, the portion of the margin thereof which enters the tube 18 increases correspondingly until the entire periphery of the tubular fabric is within tube 18, as shown on FIG. 4. From then on the tubular fabric is tensioned by the stream of air blown through the tube 18 in the upward direction. As the formation of the stocking continues in the normal manner, the stocking progressively grows or develops within the tube 18 and, upon the completion of the stocking, that is, at the press-off cycle of the knitting machine, the stocking is detached from the needles 8 so that the flow of air through the tube 18 can convey the completed stocking through the tube to any desired collection point, for example, to a basket 27 disposed under the end of tube 18 remote from needle cylinder 2, as shown on FIG. 3. During the press-off cycle and the resultant conveying of the finished stocking through tube 18, it may be desirable to reduce the force of the flow of air within that tube, for example, by means of a suitably actuated valve (not shown) interposed in the tube 19.

It should be noted that, when the stocking is pneumatically tensioned according to the present invention, as described above, in which case the knitted fabric does not pass downwardly through the needle cylinder 2 but rather is made to pass directly upward from the needle cylinder through the external tube 18, the circularly knitted fabric is immediately everted as it is formed so that the stocking develops in its everted state, that is, with its right side facing inwardly within the tube 18. Thus, when the completed stocking is delivered or conveyed through tube 18, for example, to the basket 27, the next step of sewing the stocking can be immediately performed thereon, and the additional or preliminary step of everting the completed stocking, as with all previously known tensioning or takeup devices, is effectively eliminated.

The flow of air through the tube 19 and the tube 18 is very effective to tension the knitted fabric during its formation and it has been found that the requisite air flow can be produced with a centrifugal fan or blower that is no larger, and may be even smaller than the fans or blowers required in connection with previously proposed pneumatic tensioning devices. Although the tensioning device of FIGS. 1 to 4, inclusive, employs a source of air under pressure for generating the desired air flows through the space 22 and the tube 18, it is to be understood that, in accordance with the present invention, the necessary air flows may be produced by a source of vacuum or relatively low pressure, as hereinafter described in detail with reference to FIG. 6.

Since the tube 18, within which the stocking is pneumatically tensioned during its formation, extends upwardly from the top of the needle cylinder 2, the frame of the knitting machine can be constructed to dispose the upper end or head of the needle cylinder, that is, the level at which the knitting of the yarns is effected, at the height most convenient for inspection and servicing of the machine.

The cover 17, which corresponds, in its position, to the usual dial cap, may have a conventional yarn cutter and clamp mounted thereon, but such assembly is not shown in the drawings for the purpose of avoiding undue complexity of the illustration. Although the knitting machine illustrated in FIGS. 1 to 4, inclusive, does not have a dial carrying an annular series of radially disposed transfer bits of the kind that are sometimes provided for formation of a double border or turned welt on the hosiery, it is to be noted that knitting machines exist in which the function of such transfer bits is performed by the needles themselves during the initial stage of the formation of a stocking. Thus, the external tube 18 which is located eccentrioally with respect to the axis of the needle cylinder 2 in the arrangement of FIGS. 1 to 4, inclusive, and therefore is not adapted for application to a knitting machine of the type having a dial carrying transfer bits and turning in synchronism with the needle cylinder, may be applied to knitting machines of the type in which the turned welt, if desired, is produced by the needles alone, rather than by the cooperative action of the needles with transfer bits.

However, as shown on FIG. 5, a pneumatic tensioning device embodying the present invention may also be provided for conventional knitting machines of the above mentioned type in which a dial carrying transfer bits is provided for the purpose of forming a turned welt. In FIG. 5, the parts of the knitting machine corresponding to those previously described in connection with FIG. 1 are identified by the same reference numerals. In such knitting machine, the rotated drive shaft 4 has an upwardly directed extension 4a which, at its upper end, carries a gear 28. The gear 28 meshes with an idler gear 29 which, in turn, meshes with a second idler or intermediate gear 30. Both of the idler gears 29 and 30 are rotatable on stub shafts or axles carried by the framework 1 of the knitting machine. The gear 30 meshes with a gear 31 formed externally on a hollow shaft 32. The hollow shaft 32 is rotatably mounted in the framework of the knitting machine and extends vertically above the needle cylinder 2 in axial alignment with the latter. At the lower end of the hollow shaft 32 there is mounted the usual dial 33 carrying a series of radially extending transfer bits 34 which, in a conventional manner, are operative to form the turned welt of a stocking. The upper end of hollow shaft 32 is suitably connected to a tube 35 which, in turn, is connected to the inlet side of a centrifugal blower or fan (not shown), that is, a source of vacuum or suction, so as to create an air flow in the upward direction through the hollow shaft 32 and the tube 35, as indicated by the arrow 36.

It will be apparent that, with the pneumatic tensioning device illustrated on FIG. 5 and intended for use with knitting machines of the type having a dial carrying transfer bits, the upwardly directed flow of air through the hollow shaft 32 above the knitting cylinder causes the tubular knitted fabric 25 to be tensioned upwardly into the hollow shaft 32 and, as the knitting progresses into the hollow tube 35, rather than being tensioned downwardly within the needle cylinder 2, as in conventional tensioning devices. Thus, the operation of the pneumatic tensioning device illustrated on FIG. 5 is similar to that of the previously described embodiment. Since the upward flow of air indicated by the arrow 36 is caused by a source of suction or vacuum, the knitted fabric will be drawn radially inward toward the lower mouth of the hollow shaft 32 during the initial stages of formation of the fabric, and the tube 19' and circular plate 21 of the embodiment in FIG. 1 can be eliminated. However, it will be apparent that, if desired, the arrangement of FIG. 5 can be employed in connection with a source of air under pressure merely by providing such arrangement with a tube similar to the tube 19 of FIG. 1 which is connected to the source of air under pressure, and by providing such tube 19 with a plate 21 spaced downwardly from the dial 33, which then functions as the cover 17 of the first described embodiment.

As shown on FIG. 6, the pneumatic tensioning device illustrated on FIG. 1 can also be modified so that the stream of air directed upwardly through the external tube 18, as indicated by the arrow 26, results from suitable connection of the end of such tube 18 remote from the needle cylinder to a source of relatively low pressure or suction. In the arrangement of FIG. 6, the tube 19 and plate 21 of FIG. 1 are again eliminated, and the tube 18 extending upwardly from the upper end of the needle cylinder is connected, as at 41, to a casing 37 so as to communicate with a compartment 40 defined within such casing. The interior of the casing is divided by a perforated wall 39 into the compartment 40 and a compartment 42 which is in communication with an outlet connection 43. The outlet connection 43 is connected by a tube 44 to the inlet 45 of a centrifugal fan or blower 46 which operates to create a suction or relatively low pressure at the inlet 45. A valve 47 is located in the outlet connection 43 of casing 37 for movement between open and closed positions, and the compartment 40 of the casing is provided with a door 38 movable from the closed position shown in full lines to an open position indicated by the broken lines.

During knitting of a stocking 25, the door 38 is maintained in its closed position and the valve 47 is open so that the suction created at the inlet 45 of the blower 46 causes a flow of air through the tube 18 in the direction from the needle cylinder into the compartment 40 of casing 37, as indicated by the arrow 26, from compartment 40 through perforated wall 39 into the compartment 42, and from compartment 42 through tube 44 to the inlet of the blower. Such flow of air attracts the tubular knitted fabric during the formation thereof, and draws the fabric upwardly into the tube 18 so as to tension the knitted fabric. Upon completion of a stocking, that is, during the press-off cycle of the associated knitting machine, the air flow through tube 18 conveys the completed stocking into the compartment 49 of casing 37. Upon the delivery of the completed stocking to compartment 40, valve 47 is closed and door 38 is opened, for example, by actuating mechanisms (not shown) under the control of the usual cams of the knitting machine, so that the completed stocking is ejected or falls into a collecting vessel or basket (not shown) disposed under the casing 37.

It will be apparent that, in the arrangement of FIG. 6, as in the previously described embodiments of this invention, the upward tensioning of the stocking within the tube 18 ensures that the stocking, as knit, will have its right side facing inwardly, thereby to avoid the necessity of exerting the completed stocking prior to the subsequent sewing step. As in the previously described embodiments, the arrangement of FIG. 6 makes it possible to considerably reduce the height of the knitting machine since each stocking being knit is directed generally upwardly from the upper end of the needle cylinder, rather than hanging downwardly and issuing from the bottom of the needle cylinder, as in previous tensioning devices. Thus, the head of the knitting machine can be located at the height most suitable for easy inspection and servicing of the knitting machine.

The several illustrated embodiments of the invention have the associated knitting machines arranged with their needle cylinder axes extending vertically, as in all existing knitting machines, but it will be noted that the pneumatic tensioning devices embodying this invention make it possible to arrange the needle cylinder with its axis inclined or even horizontal.

Although illustrative embodiments of this invention have been described in detail herein with reference to the accompanying drawings, it is to be noted that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, except as defined in the appended claims.

What is claimed is:

1. In a circular knitting machine having a cylinder bearing an annular series of needles, and sinkers cooperating with the needles to form the stitches of a circular knit fabric adjacent one end of said cylinder; a pneumatic tensioning device comprising means operative to produce a flow of air from the interior of said cylinder to the exterior thereof generally in the axial direction extending toward said one end of the cylinder from the other end thereof, whereby said flow of air is adapted to tension fabric as it is knit and to pull the knit fabric out of said cylinder at said one end of the latter.

2. In a circular knitting machine having a generally vertical cylinder bearing an annular series of needles, and sinkers cooperating with the needles to form the stitches of a circular knit fabric adjacent the upper end of said cylinder; a pneumatic tensioning device comprising means operative to produce a flow of air upwardly through said cylinder to the exterior of the latter at said upper end of the cylinder, whereby said flow of air is adapted to tension fabric as it is knit and to draw the knit fabric upwardly out of said upper end of the cylinder.

3. In a circular knitting machine having a cylinder bearing an annular series of needles, and sinkers having edges defining a sinking plane and cooperating with the needles to form the stitches of a circular knit fabric adjacent one end of the cylinder; a pneumatic take-up device comprising a tube arranged outside of said cylinder and extending generally in the axial direction away from said one end of the cylinder, said tube having an open end lying substantially in said sinking plane, and means op erative to produce a flow of air into said open end of the tube and through the latter in the direction away from said cylinder so that said flow of air tensions the fabric as it is knit and conveys the knit fabric out of said cylinder through said tube.

4. In a circular knitting machine, a pneumatic takeup device as in claim 3; wherein said means operative to produce the flow of air through said tube includes a pipe in said cylinder having an end terminating adjacent, and opening in the axial direction toward said open end of the tube with an annular gap being defined between the adjacent ends of the tube and pipe, and a source of air under pressure connected to said pipe to cause a flow of air through the latter and into said tube, the flow of air through said pipe inducing additional air to flow into said tube through said annular gap.

5. In a circular knitting machine, a pneumatic takeup device as in claim 4; wherein said pipe has a nozzle at said end terminating adjacent said tube.

6. In a circular knitting machine, a pneumatic takeup device as in claim 3; further comprising a cover substantially closing said one end of the needle cylinder approximately at said sinking plane and having an opening through which said open end of the tube projects.

7. In a circular knitting machine, a pneumatic takeup device as in claim 6; further comprising a wall fixed within the cylinder and extending parallel to said cover to define a space therebetween in which the stitches of the circular knit fabric are formed; and

wherein said means operative to produce a fiow of air through said tube includes a pipe in said cylinder having an end projecting through said wall and having an end terminating adjacent, and opening in the axial direction toward said open end of the tube with an annular gap being defined between the adjacent ends of the tube and pipe and communicating with said space, and a source of air under pressure connected to said pipe to cause air to issue forcefully from said pipe into said open end of the tube and thereby induce the flow of air from said space into said open end of the tube for further urging the circular knit fabric into the tube.

8. In a circular knitting machine, a pneumatic takeup device as in claim 6; wherein said open end of the tube is arranged eccentrically with respect to said cylinder.

9. In a circular knitting machine, a pneumatic takeup device as in claim 3; wherein said means operative to produce a flow of air includes a source of vacuum, and means connecting said source of vacuum with the other end of said tube.

10. In a circular knitting machine, a pneumatic takeup device as in claim 9; wherein said means connecting the source of vacuum with said other end of the tube includes means defining a chamber at said other end of the tube, a conduit extending from said chamber to said source of vacuum, a perforated wall between said chamber :and conduit, a door on said chamber through which knitted fabric drawn into said chamber can be removed, and valve means in said conduit for interrupting the action of the vacuum when said door is opened.

11. In a circular knitting machine having a cylinder hearing an annular series of needles, sinkers having edges defining a sinking plane and cooperating with the needles to form the stitches of a circular knit fabric adjacent one end of the cylinder, and a dial carrying a radial series of transfer bits for cooperation with the needles in producing a turned welt; a pneumatic take-up device comprising a tube arranged outside of said cylinder and extending generally in the axial direction away from said one end of the cylinder, said tube including a section constituting a hollow shaft supporting said dial and having an open end lying substantially in said sinking plane, and means operative to produce a flow of air into said open end of said section of the tube and through the latter in the direction away from said cylinder so that said flow of air tensions the fabric as it is knit and conveys the knit fabric out of said cylinder through said tube.

12. In a circular knitting machine having a generally vertical cylinder bearing an annular series of needles, and sinkers having edges defining a sinking plane and cooperating with the needles to form the stitches of a circular knit fabric adjacent the upper end of the cylinder; a pneumatic take-up device comprising a tube arranged outside of said cylinder and extending generally in the axial direction upwardly away from said upper end of the cylinder, said tube having an open end lying substantially in said sinking plane, and means operative to produce a flow of air upwardly into said o en end of the tube and through the latter in the direction away from said cylinder so that said flow of air tensions the fabric as it is knit and conveys the knit fabric out of said cylinder through said tube.

13. In a circular knitting machine, a vertically disposed needle cylinder, and a vertically arranged tubular member arranged in axial alignment with the upper end of said needle cylinder and having produced therein an upwardly extending air stream to draw into said tubular member the knitted material as it is knitted by meshforming parts on said needle cylinder.

References Cited UNITED STATES PATENTS 2,844,952 7/1958 WaWZOner 66-147 MERVIN STEIN, Primary Examiner.

R. FELDBAUM, Assistant Examiner.