US3685317A

US3685317A - Device for tensioning stitches being formed in hosiery dual-bed flat machines

Info

Publication number: US3685317A
Application number: US91122A
Authority: US
Inventors: Alfredo Giachetti; Enzo Maranghi; Lastra A Signa; Angiola Pieracci
Original assignee: G Billi and C SpA
Current assignee: G Billi and C SpA
Priority date: 1970-11-19
Filing date: 1970-11-19
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22

Abstract

In a flat bed knitting machine having spaced inclined needle beds wherein a cam carriage moves back and forth along the needle beds to reciprocate the needles to form stitches thereon, during which the needles of both beds thereof cross each other as the knitting waves of the needles move back and forth along the needle beds, the combination therewith of a pair of rod-like stitch tensioning stems supported by, and movable with, the cam carriage, each stem having a free end portion extending parallel to the direction of travel of the cam carriage with the free ends laterally positioned and extending in opposite directions, the stems being interchangeably movable into, and out of, operative positions between the needle beds wherein the operatively positioned stem is beneath the crossed needles, and is in contact with, and exerts pressure upon, the stitches on the crossed needles of the knitting waves. The machine has means to interchangeably position the stems at each end of the cam carriage stroke, so that as the cam carriage moves in each of its directions of travel, the stem having its free end extending in the opposite direction is placed into operative position.

Description

United States Patent Giachetti et al.

[ 51 Aug. 22, 1972 [54] DEVICE FOR TENSIONING STITCHES BEING FORMED IN HOSIERY DUAL- BED FLAT MACHINES [72] Inventors: Alfredo Giachetti; Enzo Maranghi; Lastra A. Signa; Angiola Pieracci, all of Staffoli, Italy [73] Assignee: G. Billi & C. S.p.A., Firenze, Italy [22] Filed: Nov. 19, 1970 21 Appl. No.: 91,122

[52] U.S.Cl ..66/64 [51] Int. Cl. ..D04b 7/04 [58] Field of Search ..66/ 147, 60, 64

[56] References Cited UNITED STATES PATENTS 3,049,900 8/1962 Bram ..66/60 3,007,324 11/1961 Bram ..66/64 3,153,922 10/1964 Bram ..66/64 Primary Examiner-Ronald Feldbaum AttorneyLouis Necho ABSTRACT In a flat bed knitting machine having spaced inclined needle beds wherein a cam carriage moves back and forth along the needle beds to reciprocate the needles to form stitches thereon, during which the needles of both beds thereof cross each other as the knitting waves of the needles move back and forth along the needle beds, the combination therewith of a pair of rod-like stitch tensioning stems supported by,- and movable with, the cam carriage, each stem having a free end portion extending parallel to the direction of travel of the cam carriage with the free ends laterally positioned and extending in opposite directions, the stems being interchangeably movable into, and out of,

operative positions between the needle beds whereinv the operatively positioned stem is beneath the crossed needles, and is in contact with, and exerts pressure upon, the stitches on the crossed needles of the knitting waves. The machine has means to interchangeably position the stems at each end of the cam carriage stroke, so that as the cam carriage moves in each of its directions of travel, the stem having its free end extending in the opposite direction is placed into operative position.

5 Claims, 17 Drawing Figures PATENTEDwszz m2 SHEET 1 0F 7 22 3A V 2A 9 7/0.

I L. w 12 3 l 9 v I N v E NTO R s ALFREDO Gincusrri, [v20 MnRANsni, ANeiow RERRCCL ATTORNEY iQ M PATENTEDwszz I912 3.685317 SHEET 2 [IF 7 INVENTORS ALFREDQGimmfrri Euzo MHRHNGHI; ANG IOLO PERAccI ATTORNEY memanwsez 1912 3.68531 7 SHEET 3 [1F 7 Fig.7A

INVENTORS ALFRmGiAcHETri, EuzoMaaqneui Ausl oLo Emacs ATTORNEY PATENTED M1822 I97? 3; 685; 3 1 T SHEET t [If 7 Fig. 9

INVENTORS ALFREVOCIhCHETTI; EMZOMARMGHJ', AueioLo PERncci n T T o R N E Y PATENTEDAum I912 3685317 SHEET 5 UF 7 INVENTORS I ALFREDO GIhcHETTI Euzo MHRRNGHI, AusiowRzRncci A-r-roRN EY 951w w mmsnmzm" 3.685317 SHEET 6 OF 7 Fig. 13

I N VE N To R S ALFREDO GiAcHEn-I, Euzo MRRHNGHL Aueiow mRAcci BTIVORNEY PATENTEDAHEZZ 1912 1685317 SHEET 7 OF 7 Fig. 15

Fig.16

INVENTORS ALFREDO BiAcHETTi, Euzo MHRANQHL Ausibm PERncci ATTORNEY DEVICE FOR TENSIONING STITCHES BEING FORMED IN HOSIERY DUAL-BED FLAT MACHINES The present invention relates generally to the art of knitting, and more particularly to flat independent latch needle knitting machines of the type having opposed inclined needle beds, and to the provision in such machines of means to exert tension directly upon the stitches on the shanks of the needles, thereby to assist in the latch clearing and the casting-off of the stitches from the needles.

In the type of machine above set forth, wherein the needles of each bed thereof cross each other during the knitting operation, it has been the practice to use weights, or to use a take-up apparatus on the fabric being produced by the machine in order to assist in the stitch formation on the needles. It has also been the practice to use a starting comb on the machine to assist in the formation of the first courses of fabric being made upon the machine.

It is the principal object of the present invention to provide means to automatically assist in the formation of stitches in fabrics, and in the starting courses of fabrics made upon the type of machine above set forth, without the use of weights, fabric take-up apparatus, or starting combs.

It is also an object of the present invention to provide stitch-tensioning means upon, and movable with, the reciprocating cam carriage used on the type of machine above set forth which will be in direct contact with, and will exert tension upon, the stitches on the shanks of crossed needles in the knitting waves thereof, thereby to aid in the knitting process upon the needles of the machine.

With the above and other objects of the present invention in view, as will be readily apparent from the following detailed description of the preferred embodiments thereof shown in the accompanying drawings, the invention resides in the stitch-tensioning means for flat bed knitting machines as illustrated and described, and as set forth in the appended claims.

In the drawings:

FIG. 1 is a schematic plan view of the two parallel needle beds of a flat knitting machine, and of the reciprocating cam carriage associated with the needle beds to actuate the needles, and showing a pair of stitch-tensioning members of the present invention in place upon opposite sides of the cam carriage.

FIG. 2 is a view, similar to FIG. 1, of one end of the machine with the cam carriage at the corresponding end of the needle beds with one of the stitch-tensioning members in operative position, and with the other of the stitch-tensioning members out of operative position.

FIG. 3 is a view, similar to FIG. 1, of the opposite end of the machine with the cam carriage at the corresponding end of the needle beds and with the operative and non-operative positions of the stitch-tensioning members reversed.

FIG. 4 is a cross-sectional view of the machine as taken along the line IV-lV of FIG. 1.

FIG. 5 is an enlarged detail view of a portion of FIG. 4 showing the relationship between the pair of stitchtensioning members of the present invention and the needle beds.

FIG. 6 is a view similar to FIG. 5, showing an intermediate position of the present stitch-tensioning members as they are moved into, and out of, their operative positions.

FIG. 7 is a perspective view of one of the stitch-tensioning members of the present invention and its suptensioning member being shown in cross-section as taken along line VIII-VIII of FIG. 7.

FIG. 9 is a plan view similar to FIG. 1, showing a modified form of means to place the stitch-tensioning members of the present invention into, and out of, their operative positions.

FIG. 10 is an enlarged view of one end of the machine of FIG. 9.

FIG. 11 is a cross-sectional view of the machine as taken along the line Xl-XI of FIG. 9.

FIG. 12 is an enlarged view, partly in section, showing the modified means to place the present stitch-tensioning members into, and out of, their operative positions.

FIG. 13 is a view similar to FIG. 12, showing an intermediate position of the stitch-tensioning members as they are moved into, and out of, their operative positrons.

FIG. 14 is a perspective view of one of the stitch-tensioning members of the present invention along with its support and operating means.

FIG. 15 is a cross-sectional view of the operating means for the stitch-tensionin g members as taken along line XV-XV of FIG. 13; and

FIG. 16 is a view similar to FIG. 15, as taken along line XVIXVI of FIG. 13.

The stitch-tensioning members of the present invention and a first means of operating the same are shown in FIGS. 1 to 8 as having been applied to an otherwise conventional two-bed flat independent latch needle knitting machine wherein the needle beds are inclined. The machine frame, indicated at 1, suitably supports a pair of spaced parallel rectangularly

shaped needle beds

3 and 3B which are symmetrically inclined relative to a vertical plane A-A midway therebetween. The needle beds are each provided with a series of spaced transversely extending parallel slots 5, FIG. 5, within which latch needles 7 are adapted to reciprocate, it being understood that when the needles of the two needle beds are moved toward their latch clearing positions, they cross each other as shown in FIG. 8. The yarn, indicated at Y, is fed to the needles by a yarn guide 8 which is mounted upon and moves with reciprocating cam carriage 2 of the machine. The cam carriage is provided with a pair of oppositely positioned

cam plates

9 and 9A, each of which is provided with the necessary cams to cause the needles to move through their normal knitting waves. The cam plate 9 is associated with the needles of bed 3 and the cam plate so that the latter and the cam carriage maybe moved- I back and forth along the rails and the needle beds.

A pair of like stitch-tensioning members of the presentinvention are indicated at 10 and 12 with the former mounted upon cam plate 9A and the latter mounted upon cam plate 9. Thev memberl and its supporting bracket is shown in FIG. 7, and it will be understood that the'description thereof will also suffice for the member 12. The supporting bracketcompn'ses a block or plate 11 and a rib 13 depending therefrom.

the boss 18 of member engages cam face 22A. The

The member 10 is generally L-shaped and has its base portion suitably formedto be slidably retained in a dovetail groove 10A, FIG. 7A, formed in and extending transversely of the plate 11 w'hereb'y'the member 10- may be moved transversely of the direction of travel of the cam carriage. The member 10 is placed in position at the right'hand side of cam plate 9A, FIGS. 1-3, by

suitably securing rib 13 to the upper right-hand side of the cam plate. The member 10 is also provided with a freely extending stem portion 110 positioned at' right angles to its base portion in the plate 11 sothat the stem lloextends parallel to the direction of travel of the cam carriage and is disposed in the vicinity of the upper ends of the needle beds. The member 12 is similarly mounted upon the left-hand-portion of cam plate 9 so that its stem 112 extends toward the right in parallel opposed relation to the'stem 110 which extends toward the left, FIGS. 'l-3.

The base portions of the members 10 and-l2 are provided with upstanding cylindrically shaped

bosses

18 and 20, respectively. Set screws 16 are threadedly engaged in suitable apertures formed in the bosses l8 and 20 and serveto suitably tension coil-springswhich are disposed in second and smaller apertures extending through the bosses and the base portions. The coil springs yieldingly press balls 14 against the bottoms of the slots in the'plates 11 within which the base portions of the

members

10 and 12 are slidingly disposed. It will be noted that there is a pair of spaced depressions 14A and 148 formed in the platesll within which the balls 14 may be seated when the

members

10 and 12 are moved transversely of the cam plates. Such transverse movement is imparted to the

members

10 and 12 by elongated

stationary cam members

22, 24, 26, and 28, secured to the end portions of the uppermost pair of rails 3A. The

cams

26 and 28 have angled

faces

26A and 28A which extend toward each other and which are positioned so as to engage the boss 2001 member 12 as the cam plate 9 moves to each end of the cam face 26A acting on boss 20 moves member 12 I transversely to its non-operative position, FIG. 5, in which ball 14 is seated in depression 148, and stem 112 is moved laterally away from vertical plane A-A. At the same time, cam face 22A acting on boss 18 moves member 10 transversely to its operative position, FIG. 5, in which ball14 is seated in depression 14A, and stem 110 is moved laterally toward, and into, the vertical plane A-A between the needle beds. It will be understood that the

members

10 and 12 are maintained in their respective positions by the seated balls 14.

Conversely, when the cam carriage moves to the right, FIG. 3, the boss 20 of member 12 engages cam face 28A while the'boss 18 of member 10 engages cam face 24A. The cam face 24A acting on boss 18, moves member 10 transversely to its non-operative position in which ball 14 is seated in depression 148, and stem 1 l0 is'moved laterally awayfrom vertical plane A-A. At the same time, cam face 28A acting .on boss 20, moves member 12 transversely to its operative position in which ball 14 is seated in depression 14A, and stem 1 12 is moved laterally into operative position between the needle beds, as in FIGS. 1 and 4. In FIG. 6, the

members

10 and 12 are in mid-positions, with the ball 14 midway between the

depressions

14A and 143, as the member 12 is being moved, in the direction of its arrow, toward operative position; and as the member 10 is being moved, in the direction of its arrow, toward non-operative position. The arrangement is such that when the cam carriage moves to the left, FIG. 1, the member 12 is in operative position, with member 10 in non-operative position, and that when the cam carriage moves to the right, FIG. 2, the member 10 is in operative position with the member 12 in non-operative position. Also, thatmembers 10 and 12 are so operated that when each thereof is in operative position, the free end of its stem extends in the direction opposite to the direction of travel of the cam carriage.

The cams on the

cam plates

9 and 9A actuate the needles in both beds to form knitting waves of the neemachine. Similarly, the

cams

22 and 24 have angled the stem 112 of member 12- isin operativeposition between the needle beds, and stem 110 of member 110 is in non-operative position laterally of the needle beds,

the boss 20 of member 12 engages cam face 26A while I dles as the cam carriage moves back and forth across the machine, the knitting waves moving with the carriage. The moving knitting wave, which is caused by the needles reciprocating between stitch-forming and latch-clearing positions, is formed in the space between the closed end of the stem and the closed end of the stem 112. Thus, since the needles rise after the passage of the closed end of the stem 1 10 or of the stem 1 12, depending upon the direction of travel of the cam carriage, they are raised and cross each other in the space above the moving stems, as in FIG. 8. In doing so, the stem 110 (and 112), acts as a depressor to hold down stitches C on the shanks of needles 7 as the latter are progressively raised and, also to hold the stitches C as yarn is drawn by the progressively descending needles to form new stitches to be drawn through the stitches .C. By the time the newly formed stitches are drawn, and the needles have moved to lowered position, the free tapered end of the stem 110 (and 112), has passed by the lowered needles as the knitting wave and the cam carriage moves along the needle beds. As shown in FIG. 8, the cross-section of the stem 110 (and 112), is preferably such that its upper portion is provided with a pair of flat surfaces having the same inclination as that of the needle beds, while its lower portion is arcuately shaped to slide along the stitches C. The stem 110 (and 112), is disposed so as to be very close to the needles passing thereover, and so as to exert downward pressure or tension on the stitches C of the fabric M. to aid in the stitch formation and to act as a take-up for the fabric.

In the apparatus described, the stitch-tensioning stems 110 and 112 are adapted to be placed into, and out of, their operating positions only when the cam carriage is at the ends of its stroke. Other apparatus, to place the stitch-tensioning members into, and out of, operative positions at any place along the needle beds at corresponding positions of the cam carriage stroke, is shown in FIGS. 9-16. In the modification of FIGS. 9-16, the stitch-tensioning members are given a compound motion so as to be entered between, and to be withdrawn from, the needle beds. It will be understood that the stitch-tensioning stems of the members of FIGS. 9-16 act upon the stitches C on the needles in the same manner as those shown in FIGS. 1-8. Inasmuch as the apparatus used upon each of the pair of cam plates in FIGS. 9-16 is similar, like characters have been used for similar parts thereof, and it will be sufficient to describe the means used for the positioning of one, only, of the stitch-tensioning members.

In FIGS. 9-16, a two-bed flat knitting machine is shown in which the slotted needle beds thereof are indicated at 121. The upper ends of the walls between the needle bed slots have conventional shoulders 121A, FIG. 12. The pair of cam plates of the cam carriage are indicated at 123, with the carriage itself moving back and forth along rails 125 located above the needle beds. The cams on the cam plates 123 actuate the needles in the same manner as the cams on the

cam'plates

9 and 9A of FIGS. 1-8.

A bracket 127, FIG. 12, is secured to each of the cam plates 123, and a block 129 is supported by each bracket so as to overhang theupper end of each cam plate 123. The arrangement is such that one block 129 is at one end of one cam plate 123, while the other cam block 129 is at the opposite end of the other cam plate 123. Each block 129 provides a housing for a stitchtensioning member 137 and its operating means, and to this end the block 129 is slotted as at 131, to receive the member 137 between the side walls of the slot. Each member 137 is provided with a forwardly extending stem 139, similar to the

stems

110, 112, of FIGS. 1-8. The member 137 is provided at its tail-end with a depending slotted bracket 141, and with a depending apertured bracket 149 spaced from the bracket 141. A pin 133 extending between, and anchored in the walls of housing 129 passes freely through slot 143 of bracket 141. A drum 135, rotatably joumalled in the side walls of housing 129, is also slotted as at 145, to receive the member 137 and its bracket 149 therein. The side walls of the slot 145 have a pin 147 extending therebetween with the pin 147 extending freely through the aperture in bracket 149 of the member 137. The drum 135 is provided with a shaft 135A of reduced diameter extending beyond the housing 129, and upon which is fixed a geared pinion 151. The pinion 151 meshes with, and is turned by, the teeth of a rack 153A formed on a rod 153, the latter being adapted to reciprocate in a direction normal to the direction of travel of the cam carriage, as shown by the arrow f10, FIGS. 13, 14. Each rod 153 is supportingly guided at one end thereof in a bracket 155, FIGS. 10, l l, on a cam plate 123, and at the other end thereof by a pin 157 extending freely through a slot in the rod 153 and anchored in a flange on the bracket 127.

It will be noted that lengthwise movements of the rack rod 153 will cause back-and-forth partial rotations of the drum and, accordingly, there will be backand-forth arcuate movements of the off-center pin 147. As the pin 147 is arcuately moved between its limit positions, (shown at the left-hand and right-hand sides of FIG. 12), it accordingly moves member 137, (and stem 139), toward, and away from, the needle beds, the member 137 at the same time being pivotally movable about, and lengthwise movable along, the pin 133. This results in arcuate movements for the stem 139 which permits the latter to be placed into, and out of, operative position between conventional needle beds. The operative position of one stem 139 is shown at the lefthand of FIG. 12, while the inoperative position of the other stem 139 is shown at the right-hand side of FIG. 12. It may be noted, FIG. 13, that when the rack rods 153 are at the mid-points of their strokes, the members 137 position their stems 139 above the needle beds 121. The free and closed ends of the stems 139 have the same relation to the cam plates 123, as-the

stems

110 and 112 have in relation to the

cam plates

9 and 9A of FIGS. 1-8.

The portion of the rack rods 153 extending through their supports 155 are each provided with one or more pairs of spaced rollers 159, FIGS. 10, 11, which straddle horizontally extending rails 161. The rails 161 project upwardly from the faces of horizontally extending plates 163, disposed on each lateral side of the needle beds. Each plate 163 has a pair of spaced offset slots 165 therein, and through which pins 167 freely extend, the pins 167 extending upwardly from, and being supported by, suitable brackets 169 affixed to the respective needle beds. The plates 163 are thus slidingly supported on the brackets 169 and are capable of endwise movement relative thereto within the limits of the slots 165. The shape of the slots 165 is such that endwise movement of the plates 163 will cause the latter to assume each of a pair of laterally offset positions, depending upon the direction in which the plates 163 are moved. Such movement of the plates 163 between its lateral positions causes the rails 161 to move in a direction normal to the direction of travel of the cam carriage, and this causes the rack rods 153 to reciprocate. Such movement of rack rods 153 causes the stitch-tensioning members 139 to be moved into, and out of, their operative positions.

The plates 163 may have appropriate endwise movement imparted to them by a pattern mechanism of any suitable type, such as indicated at 170 in FIG. 9, at one end of the machine. Each of the plates 163 is suitably connected at one end thereof to the pattern mechanism 170, by pull rods or wires 171, while the other ends of the plates 163 are each suitably connected to one end of a tensioned spring 173, of which the other end is suitably anchored on the frame of the machine. Thus, under pattern control, the plates 163 may be moved back and forth between their end positions at any time during the stroke of the cam carriage, accordingly to move the rack rods 153 by the lateral movement of the rails 161. Consequently, the positions of the stems 139 may be reversed in any position of the cam carriage along the needle beds where it is desired to reverse the movement of the cam carriage. The positions of the two plates 163 being under pattern control, their movements are timed so that interference between the stems 139 is avoided. If desired, the movements of plates 163 may be such as to provide for intermediate inactive positions of both stems 139, as in FIG. 13, or the movements of the plates 163 may be such as to provide for fully inactive positions of both stems 139, such as is indicated for one of the stems at the right-hand side of FIG. 12.

What we claim is:

1. In a flat knitting machine of the type having a pair of spaced inclined needle beds, said needle beds being slotted, latch needles adapted to reciprocate in the slots of said needle beds to form stitches thereon, a cam carriage adapted to move back and forth along said needles beds, said cam carriage having a pair of cam plates movable therewith, said plates being individually associated with said pair of needles beds to reciprocate the needles in each of said needle beds to form knitting waves thereof during which said stitches are formed on said needles, said knitting waves also moving back and forth along said needle beds during which the hook ends of the needles in said knitting waves cross each other, and the combination therewith of a pair of stitchtensioning members individually mounted upon said pair of cam plates and movable with said cam carriage back and forth along said needle beds, each of said pair of members being generally L-shaped with one arm of the L-shape providing an elongated free end portion of said member and with the other arm of the L-shape providing a base portion of said member, said pair of members being individually mounted upon said pair of cam plates in such manner that said free end portions thereof extend generally parallel to the direction of travel of said carriage and that said base portions thereof are movable normally to the direction of travel of said cam carriage, said free end portions of said members being laterally positioned and extending in opposite directions, said base portions of said members being so normally movable at each end of the stroke of said cam carriage thereby. to interchangeably place said free end portions of said members into and out of operative positions at each end of the stroke of said cam carriage, the free end portion of the operatively placed one of said members being disposed between said needle beds and beneath said crossed needles in said knitting waves in contact with the stitches on said crossed needles thereby to exert tension thereon, the free end portion of the operatively placed one of said members extending in the direction opposite to the direction of travel of said cam carriage.

2. In a knitting machine as in claim -1 wherein the base portions of said members are each provided with a roller extending upwardly therefrom, wherein said machine is provided with a pair of cams at each end of said needle beds, and wherein the pair of cams at each end of said needle beds is adapted to engage said rollers at each end of the stroke of said cam carriage to move the base portions of said members in said direction t er toi terc an ea 1 la e 'd free nd 0 ions 0 sai inem rs iiito an ofsa ifi operative p bsiiions thereof.

3. In a knitting machine as in claim 1 wherein said free endportions of said members follow curved paths in their movements into and out of said operative positions thereof, and wherein said curved paths are effected by imparting an arcuate movement to one end of the base-portions of said members while at the same time imparting a sliding and pivotal movement to the other end of said base portions.

4. A knitting machine as in claim 3 wherein a housing is provided on each of said cam plates, wherein said housing is provided with walls defined by a slot therebetween, wherein a pin is supported by the walls of said housing and extends across said slot thereof, wherein a drum is rotatably mounted in the walls of said housing and extends across said slot thereof, wherein said drum is provided with walls defined by a slot therebetween, wherein an eccentrically positioned pin is supported by the walls of said drum and extends across said slot thereof, wherein the base portion of one of said members is disposed in said slots in said drum and in said housing, wherein said one end of the base portion of said member is provided with a transversely extending aperture through which said drum pin freely extends, and wherein said other end of said base portion is provided with a lengthwise extending slot through which said housing pin freely extends.

5. A knitting machine as in claim 4 wherein a rack and pinion are operatively related to said drum, wherein said rack is adapted to be reciprocated in the direction normal to the direction of travel of said cam carriage to oscillate said drum, wherein a rail is provided so as to extend parallel to the direction of travel of said cam carriage, wherein said rack is operatively related to and moves back and forth along said rail, and wherein said rail is laterally movable thereby to reciprocate said rack and to oscillate said drum.

Claims

1. In a flat knitting machine of the type having a pair of spaced inclined needle beds, said needle beds being slotted, latch needles adapted to reciprocate in the slots of said needle beds to form stitches thereon, a cam carriage adapted to move back and forth along said needles beds, said cam carriage having a pair of cam plates movable therewith, said plates being individually associated with said pair of needles beds to reciprocate the needles in each of said needle beds to form knitting waves thereof during which said stitches are formed on said needles, said knitting waves also moving back and forth along said needle beds during which the hook ends of the needles in said knitting waves cross each other, and the combination therewith of a pair of stitch-tensioning members individually mounted upon said pair of cam plates and movable with said cam carriage back and forth along said needle beds, each of said pair of members being generally L-shaped with one arm of the L-shape providing an elongated free end portion of said member and with the other arm of the L-shape providing a base portion of said member, said pair of members being individually mounted upon said pair of cam plates in such manner that said free end portions thereof extend generally parallel to the direction of travel of said carriage and that said base portions thereof are movable normally to the direction of travel of said cam carriage, said Free end portions of said members being laterally positioned and extending in opposite directions, said base portions of said members being so normally movable at each end of the stroke of said cam carriage thereby to interchangeably place said free end portions of said members into and out of operative positions at each end of the stroke of said cam carriage, the free end portion of the operatively placed one of said members being disposed between said needle beds and beneath said crossed needles in said knitting waves in contact with the stitches on said crossed needles thereby to exert tension thereon, the free end portion of the operatively placed one of said members extending in the direction opposite to the direction of travel of said cam carriage.

2. In a knitting machine as in claim 1 wherein the base portions of said members are each provided with a roller extending upwardly therefrom, wherein said machine is provided with a pair of cams at each end of said needle beds, and wherein the pair of cams at each end of said needle beds is adapted to engage said rollers at each end of the stroke of said cam carriage to move the base portions of said members in said direction thereby to interchangeably place said free end portions of said members into and out of said operative positions thereof.

3. In a knitting machine as in claim 1 wherein said free end portions of said members follow curved paths in their movements into and out of said operative positions thereof, and wherein said curved paths are effected by imparting an arcuate movement to one end of the base portions of said members while at the same time imparting a sliding and pivotal movement to the other end of said base portions.