WO2001040560A1

WO2001040560A1 - Plating yarn carrier assembly

Info

Publication number: WO2001040560A1
Application number: PCT/US2000/032155
Authority: WO
Inventors: Ernesto H. Brach; Joshua Benin; Grant Warner
Original assignee: E.I. Du Pont De Nemours And Company
Priority date: 1999-11-30
Filing date: 2000-11-28
Publication date: 2001-06-07

Abstract

This invention relates to a yarn carrier (10) for a flat knitting apparatus having a yarn deflector (100) with a notch (100 H) formed therein. The yarn deflector is mounted to the yarn carrier for movement with respect thereto from a first, retracted, to a second, extended, position. Movement of the deflector (160) from the retracted to the extended positions causes one of the yarns (S) to become engaged within the notch thereby changing the magnitude of the angle between the hard and soft yarns (H, S) carried by the yarn carrier.

Description

TITLE PLATING YARN CARRIER ASSEMBLY

BACKGROUND OF THE INVENTION

This invention relates to a yarn carrier for a flat knitting apparatus for knitting plated fabrics.

DESCRIPTION OF THE PRIOR ART "Plating" means the feeding of two yarns simultaneously to the needles of a knitting apparatus in such a way that there are two loops in each stitch, one from each yarn. These loops are positioned so that one loop is on one side of the stitch and the other loop is on the other side. The yarns may be either contrasting in color or having different fibrous compositions. For example, it is not unusual to plate a so-called "hard" yarn (such as nylon) with an elastomeric, or "soft" yarn. A suitable "soft" yarn is the elastomeric yarn manufactured and sold by E . I. du Pont de Nemours and Company under the registered trademark Lycra®.

The plated effect is obtained by ensuring that the two plating yarns are fed to the needles at an angle, typically in the range from between fifteen to forty- five degrees (15° and 45°) , measured from the point on the inside surface of the needle where the two yarns meet. This angle can depend on several factors, including the type of yarns being plated, stitch fabric construction, machine gauge, needle hook size or shape and stitch density. This angle can also be potentially important to ensure that the plated yarn (usually the elastomeric yarn) is positioned in such a manner that it not miss the point of the needle hook when it is supposed to be captured by the needle. This is especially important during the knitting of the first course of a sweater knit fabric at which time there is no yarn on the needle shank to close the needle latch and thereby trap the elastomeric yarn. The smaller the angle, the better the likelihood of capture of the plated yarn by the needle.

Co-pending PCT Application PCT/US99/20940 , filed in the United States Receiving Office on 13 September 1999, discloses the structure and operation of a yarn carrier able to permit adjustable selection of the angle defined between the hard and soft yarns. The carrier comprises a first guide member and a second guide member that are relatively movable with respect to each to adjust the angle between the yarns.

However, in use, it has been found that in some instances the position occupied by the soft yarn is such that, on the first transverse pass of the carrier across the knitting apparatus, the needles in the needle array are not able to catch the soft yarn S.

Accordingly, it is believed advantageous to provide a yarn carrier having structure to modify the position of the soft yarn on the first transverse pass of the carrier across the knitting apparatus.

SUMMARY OF THE INVENTION

The present invention is directed toward a yarn carrier having a first guide member and a second guide member that are relatively movable with respect to each other in a first direction to adjust the spacing between the ends of the passages and thereby to adjust the angle between the hard and soft yarns.

A yarn deflector having a notch formed therein is mounted to the yarn carrier for movement with respect carrier from a first, retracted, to a second, extended, position. As the deflector is moved from the retracted toward the extended position one of the yarns becomes engaged within the notch. Thus, in the extended position the magnitude of the angle between the yarns is changed. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detailed description taken in connection with the accompanying drawings, which form a part of this application, and in which:

Figure 1 is a front perspective view of the yarn carrier of the present invention;

Figure 2 is a front elevational view of the yarn carrier of Figure 1 showing the yarn deflector in the retracted position;

Figure 3 is a side elevational view of the yarn carrier of Figure 2 taken along view lines 3-3 therein while Figure 3A is an enlarged view of a portion of Figure 3 ; Figures 4 and 5 are side and front elevational views of a yarn deflector of the yarn carrier of Figure 1 shown in isolation; and

Figure 6 is a front elevational view of the yarn carrier of Figure 1 similar to Figure 2 showing the yarn deflector in the extended position.

DETAILED DESCRIPTION OF THE INVENTION

Throughout the following detailed description similar reference characters refer to similar elements in all figures of the drawings.

Figures 1 and 2 illustrate a yarn carrier generally indicated by the reference character 10 having a yarn deflector generally indicated by the reference character 100 in accordance with the present invention. The basic structure of the yarn carrier 10 is disclosed and claimed in co-pending PCT Application PCT/US99/20940, filed in the United States Receiving Office on 13 September 1999.

The yarn carrier 10 is used to guide yarns to the needles of a flat knitting apparatus. Various portions of a typical knitting apparatus are stylistically illustrated in Figure 3 to enable a more clear understanding of the structure of the carrier 10 and the relationship of the structure and movements of portions of the carrier 10 with respect to the knitting apparatus .

A typical flat knitting apparatus includes a plurality of knitting needles N. As seen in Figure 3 the knitting needles N are typically arranged in front and rear needle arrays generally indicated by reference characters 14, 16 respectively. Each knitting needle N in the front needle array 14 is individually extendable and retractable in a first plane 18, while each needle in the rear needle array 16 is extendable and retractable in a second plane 20. As any given needle extends and retracts in its respective plane, it captures the plating yarns that are presented to it. The first and the second planes 18, 20 intersect to define a intersection line 24 (Figure 2) that extends transversely across the knitting apparatus.

The front and rear planes 18, 20 define a angle 26 therebetween. It is convenient for definitional purposes to define within the apparatus a predetermined reference plane. Perhaps the most convenient plane to utilize as the reference plane is that plane 28 which bisects the angle 26 between the needle planes 18, 20 and that includes the transversely extending intersection line 24. The reference plane 28 is visible as a line in the plane of Figure 2.

The yarn carrier 10 includes a first yarn guide member 32 and a second guide member 34. A mounting bracket generally indicated by the reference character 38 carries both the first and second yarn guide members 32, 34. The bracket 38 includes a generally C-shaped clamp member 38C having a base 38B from which extend a pair of clamping arms 38A. The ends of each clamping arm 38A are bent toward each other to define holding flanges 38F. One of the arms 38A has an access gap 38G therein. The gap_38G defines working surfaces 38W' for a purpose to be described. The upper face of one of the clamping arms 38A is indicated by the reference character 38U.

The base 38B of the clamp 38C is welded or otherwise conveniently secured (as indicated by the stipled area at 37) to one end of a generally L-shaped holder 38L. The second end of the holder 38L has an elongated slot 38S therein. A bolt 40 passing through the slot 38S in the second end of the holder 38L adjustably secures to the bracket 38 to the traversing mechanism T of a flat knitting apparatus of which the yarn carrier 10 forms a part.

The yarn guide 32 includes a pair of panels 32P that extend upwardly from the elongated flange portion 32F. The panels 32P and the surface of the flange portion 32F cooperate to define a channel 32C that extends axially over a portion of the yarn guide 32. The upper edge of one of the panels 32P has an array of spaced teeth 33 therein, for a purpose to be described. A guide pin 33P extends from the side of the panel 32P having the spaced teeth 33 thereon. The pin 33P is disposed near the lower end of the array of teeth, for a purpose to be described.

The yarn guide 34 is a slotted, generally tubular member that is slidably received, telescopic fashion, within the channel 32C formed in the yarn guide 32. As viewed in the drawings, the lower end of the yarn guide 34 having the jewel 34J therein extends axially beyond the panels 32P on the guide 32. The sidewalls 34S of the yarn guide 34 extend above the edges of the yarn guide 32. The upper edge of the sidewall 34S closer to the teeth 33 on the guide 32 also has an array of spaced teeth 35 provided therein. The spaces between the teeth 35 in the guide 34 are larger than the corresponding spaces between the spaces between the teeth 33 in the guide 32. This discrepancy in tooth spacing results in the teeth in the guides being offset from each other, for a purpose that becomes clearer herein. To assemble the carrier 10, the yarn guide 32, having the yarn guide 34 nested therein, extends slidably and telescopically through the bracket 38. A spring 39 is captured between the holder 38L of the bracket 38 and the undersurface of the flange portion 32F of the yarn guide 32. The force of the spring 39 acts through the yarn guide 32 to bias the upper edges of the sidewalls 34S on the yarn guide 34 ' against the holding flanges 38F on the clamping arms 38A. Upper and lower threaded screws 41U and 41L, respectively, act to draw together the arms 38A of the clamp 38C thereby to secure the yarn guide members 32, 34 in the described relationship within the bracket 38. The heads of the screws 41 are located to the side of the bracket 38 away from the path of the hard yarn H.

A first plating yarn, such as a "hard" yarn "H" , is supplied to the first yarn guide 32 through a porcelain grommet 48. The hard yarn H is illustrated in the drawings as a relatively heavy line. The grommet 48 is supported by an arm 48A. The arm 48A is pivotally adjustable with respect to the bracket 38 during set-up of the carrier 10. The arm 48A usually stays fixed while the carrier 10 is in use. The hard yarn H is directed by the grommet 48 toward an access opening located on the rear surface of the first yarn guide 32. The yarn H passes from the guiding portion 32G of the yarn guide 32 through a passage in the tip thereof. The yarn H deflects against a contact point on the deflecting surface 32D as the yarn H leaves the first yarn guide 32 toward the needle N. As the carrier 10 is traversed across the knitting apparatus the hard yarn H deflects against different contact points on the deflecting surface 32D.

A second plating yarn, such as an elastomeric or "soft" yarn "S", is supplied to the second yarn guide

34 over a pulley 52. The soft yarn S is illustrated in the drawings as a relatively thin line. The pulley 52 rides on a jeweled bearing (not visible) carried in a housing 54. The housing 54 is itself pivotally mounted to the second guide member 34 though a screw 54S. The second yarn S is directed by the pulley 52 toward the guiding portion 34G of the yarn guide 34. As the soft yarn S exits the passage 34Y in the tip of the second yarn guide 34 it is deflected against a contact point on the deflecting surface 34D of the jewel 34J toward the needle N. Similar to the situation with the guide 32, as the carrier 10 is traversed across the knitting apparatus the soft yarn S deflects against different contact points on the deflecting surface 34D toward the needle N.

The points, or locations, at which the respective yarns H, S exit from the ends of the passages in the respective tips 32T, 34T of the yarn guides 32, 34 are illustrated as being spaced a distance D from each other. The distance D between the yarn exit points at the ends of the passages 32Y, 34Y in the tips 32T, 34T can be measured with respect to any desired reference datum. A convenient reference datum is a reference axis 10A that extends longitudinally through the joined yarn guide members 32, 34. By the term "longitudinally" it is meant that the axis 10A extends generally parallel to the long direction of the carrier 10. The long direction may be considered the general direction in which the yarns H, S pass through the yarn guides 32, 34, or the direction of the carrier 10 as it moves toward and away from the intersection line 24. The axis 10A is preferably defined to lie perpendicular to the intersection line 24. The defined axis 10A may, but need not, lie in the reference plane 28.

The yarn exit point at the end of the passage 32Y in the tip 32T of the first yarn guide 32 lies a first distance E_x from the lower edge 38E of the bracket 38, and a second distance E₂ from the intersection line 24. The yarn exit point at the end of the passage 32Y in the tip 34T on the second yarn guide 34 is spaced a first distance F_λ from the lower edge 38E of the bracket 38, and lies a second distance F₂ from the intersection line 24. The distances Ei, E₂, F_l7 and F₂ are all conveniently measured along the reference axis 10A. As noted earlier, successfully plating a hard yarn H with a soft yarn S requires that the two plating yarns H, S exhibit a desired angular relationship with respect to each other. Only yarns that are appropriately oriented in space will be properly collected by the knitting needle N and will occupy the desired relative positions on the hook of the needle necessary for successful plating. As seen in the Figure 1 the yarns H, S should define a predetermined angle ZR with respect to each other. Typically the angle ZR lies in the range from between fifteen and forty-five degrees (15° and 45°) . As a corollary, the yarns H and S each also define an angle Zh, Zs, each as respectively measured from a suitable reference datum, such as a line indicated in the Figures by the reference character L that originates at the point Q on the inside surface of the needle N where the yarns H, S meet the needle N and which extends parallel to the intersection line 24.

However, as a practical matter, in the knitting operation variations can occur, owing either to the yarns, fabric constructions, machine gauges, needle hook size or shape or stitch density. Any of these variations can change the value of the angle ZR that is needed for producing properly plated fabric. The yarn carrier 10 is structured to permit the yarn guides 32, 34 to be relatively movable with respect to each other and to other features of the carrier. As will be developed, these relative movements impart to the carrier 10 the ability to adjust selectably the angles Zh, Zs respectively defined between each of the yarns H, S and the line L passing through the point Q on the needle N, as well as the relative angle ZR defined with respect to each other. From inspection of Figure 1 it may be observed that the angle ZR between the yarns H, S may be adjusted in a variety of ways. Most directly, the angle ZR may be modified by adjusting the distance D between the respective tips 32T, 34T of the yarn guides 32, 34. Alternatively, if the distance D is held constant, the angle ZR may be adjusted by either:

(1) adjusting the angle Zh between the hard yarn H and the reference datum L; and/or (2) adjusting the angle Zs between the soft yarn S and the reference datum L. The structure of the carrier 10 of the present invention is capable of achieving each of these adjustments . The angle ZR is adjusted by varying the distance D extant between the yarn exit points at the ends of the passages 32Y, 34Y in the tips 32T, 34T on the respective yarn guides 32, 34. First, the clamping force imposed by the threaded screws 41 is released. The guides 32, 34 are prevented from dropping from the bracket 38 by the holding force imposed by the bias spring 39. Once the clamping force is released the guide member 32 may moved with respect to the guide 34 in the direction of the arrows 58 to vary the distance D. Again, the direction of the motion of the guide 32' is generally parallel to the axis 10A of the joined yarn guides. The guide 32 is rectilinearly moved with respect to the guide 34 by inserting a levering implement, such as a flat blade driver, into the spaces between the offset teeth 33, 35 provided on the guides 32, 34, respectively. The levering action of the implement against a tooth 33 on the guide 32 (using a tooth 35 on the guide 34 as a fulcrum) displaces the guide 32 with respect to the guide 34. To alter the angles Zh and Zs, without adjusting the distance D the guide member 32 may be moved with respect to the bracket 38 in the direction of the arrows 60. Once the clamping force is released the implement may be inserted into a space between the teeth 33 on the guide 32 that are accessible through the gap 38G in the arm 38A of the bracket 38. The levering action of the implement against the working surfaces 38W causes the guide member 34 to displace with respect to bracket 38. It is noted that guides 32, 34 may be moved in one direction by levering the implement against the bottom edge of the lower arm 38A. However, relative movement of the guides 32, 34 in the opposite direction would not be possible without the presence of the working surface 38W on the upper edge of the lower arm 38A.

The structure of the invention also permits a further adjustment in the feeding the yarns to the knitting needle (s) N. In general, the first and second guide members 32, 34 are also relatively movable with respect to each other in a second direction indicated by the arrows 68A, 68B to move the yarn exit point at the end of the passage in the tip of one of the yarn guides toward or away from the reference plane 28. As will be developed this action adjusts the relative position on a needle occupied by the first and second yarns .

The actuating mechanism to effect this relative movement of the yarn guides in the second directions 68A, 68B includes a threaded thumbscrew 62, having an enlarged head 62H, that extends through the lower end of the first guide 32. The end 62E of the thumbscrew 62 engages the rear surface of the flange 34F of the first guide 34. Manipulation of the head 62H advances the end 62E of the thumbscrew 62 in the direction of the arrow 67.

Advancement of the thumbscrew 62 exerts a force on the lower end of the guide 34 to cause it to deflect relative to the guide 32 against the bias of the spring 39 in a direction 68A. The direction 68A is generally perpendicular to the plane containing the directions 58, 60. In addition, the other guide 32 also relatively moves with respect to the guide 34 in the counter direction 68B, also generally perpendicular to the plane containing the directions 58, 60. When the thumbscrew 62 is retracted the restored force generated by the spring 39 returns the guides 32, 34 to their original positions relative to each other.

The imposition of a deflecting force on the lower end of the guide 34 moves it relative to the first guide 32. This displaces the yarn exit point at the end of the passage 34Y in the tip 34T of the guide 34 toward or away from the bisecting reference plane 28. As a result the relative position of the yarns H, S in the hook of the needle N may be changed.

Once the yarns S, H are adjusted with respect to each other by virtue of the movement of the guides 32, 34 in the directions 68A, 68B, the location of the yarns H, S with respect to the hook of the needle N may be adjusted by movement of the entire carrier 10 with respect to the traversing mechanism T. This ability to adjust the plating yarn S with respect to the hard yarn H within the hook of the needle is advantageous when rib stitching is necessary, as, for example, when knitting wrist bands and waist bands of a knitted garment . Summarizing, it is appreciated from the foregoing that the yarn carrier 10 of the present invention in which the yarn guides 32, 34 are movable with respect to each other and with respect to the bracket 38 enables adjustment of the angle ZR between the hard yarn H and the soft yarn S, as well as adjustment of the angles Zh, Zs between the hard yarn H and the soft yarn S in relation to the line L through the needle N.

-o-O-o-

In the discussion that follows it is assumed that the carrier 10 is mounted to the knitting apparatus such that the direction of the first transverse pass of the carrier 10 across the apparatus occurs in the direction as indicated by the arrow 98 (Figures 2 and 6) . Accordingly, as the carrier makes its initial transverse, the left-hand side of the yarn carrier 10 as viewed in Figures 2 and 6 is the leading side of the carrier 10 and the right-hand side is the trailing side of the carrier 10.

In use, it has been found that in some instances, i.e., when making a 2x1 racked start and cuff, on the first transverse pass of the yarn carrier 10 the magnitude of the angle Zs between the soft yarn S and the line L through the needle N is too great for the needles in the needle array to catch the soft yarn S without the needle latch guiding the soft yarn into the needle hook because there is no yarn on the needle shanks to close the needle latches which, in turn, guide the soft yarn into the needle hook. To remedy any difficulty around the engagement between the soft yarn S and the needles during the first transverse pass, the yarn carrier 10 in accordance with the present invention includes a yarn deflector generally indicated by the reference character 100. The yarn deflector 100 is mounted to the right-hand, or trailing, side of the yarn carrier 10. As will be developed the yarn deflector 100 is adapted for relative movement with respect to the yarn carrier 10 from a retracted (Figure 2) to an extended position (Figure 6) . As the yarn deflector 100 moves from its retracted to its extended position the deflector 100 engages and carries the soft yarn S longitudinally along the yarn carrier 10, so that, when the yarn deflector 100 is in its extended position, the magnitude of the angle ZR between the soft and hard yarns is diminished to such an extent that the soft yarn S is able to be caught and clasped by the needles N.

As seen in Figures 1 , 2 , 4 , 5 and 6 the yarn deflector 100 is a substantially planar member formed from a spring steel or other flexible material . The upper part of the yarn deflector 100 defines a relatively enlarged arm portion 100A having an elongated mounting slot 100M formed therethrough. The arm portion 100A tapers through a transition portion 100T into a narrower, elongated deflecting finger 100F. A guide slot 100G is provided in the transition portion 100T. The lower end of the finger 100F has a notch 10ON formed therein.

The yarn deflector 100 is bent along a bend line 100L that extends across the lower margin of the arm portion 100A to define a predetermined bend angle 100P (Figure 4, on the order of one hundred sixty-five degrees) between the undersurface 100U of the arm portion 100A and the deflecting finger 100F. A rivet 10OR having an enlarged head 10OH thereon is mounted to deflector 100. The head 100H of the rivet 100R is disposed adjacent to the undersurface 100U of the arm portion 100A, while the shank of the rivet 100R projects above the outer surface 100T of the arm 100A. As may be best understood from Figure 2, to attach the deflector 100 to the yarn carrier 10 the undersurface 100U of the arm portion 100A is presented to the lateral surface of the bracket 38 on the trailing side of the carrier 10. The yarn deflector 100 is positioned such that the shanks of the screws 41 project through the mounting slot 100M formed in the arm portion 100A and so that the guide pin 33P projects through the guide notch 100G provided in the transition portion 100T. The deflector 100 is held to the carrier 10 by a nut 102 threaded to the shank of one of the screws 41. The clearance between the nut 102 and the bracket 38 permits the deflector 100 to move slidably with respect to the carrier 10 in directions parallel to the axis 10A. Mounting of the deflector 100 to the carrier 10 in the manner described serves to slightly flatten bend angle 100P of the deflector 100 (Figure 4) , thus imposing a bias on the deflector that urges the upper and lower edges of the deflector toward the trailing side of the carrier 10.

The operation of the carrier 10 in accordance with the present invention may be understood from the comparison of the relationship of the deflector 100 with respect to the carrier 10 as shown in Figures 2 and 6. It is again noted that the direction of the first transverse pass of the yarn carrier 10 across the knitting apparatus is indicated by the arrow 98. In Figures 1 and 2 the deflector 100 occupies the retracted position. In the retracted position the top edge of the guide slot 100G is spaced a predetermined clearance distance 104 from the shank of the guide pin 33P. This clearance distance 104 defines the full extent of the distance of travel of the deflector 100 with respect to the carrier 10 along the longitudinal axis 10A. The top edge of the mounting slot 100M is spaced a greater clearance distance 106 from the shank of the upper screw 41U. When retracted the head 100H of the rivet 100R is just above the upper surface 38U of the bracket 38. The bias force generated within the deflector 100 urges the head 100H inwardly (that is, toward the illustrated position of the axis 10A) . In this position the head 100H serves as a positive stop which prevents unintended longitudinal displacement of the deflector 100. When retracted the notched lower end of the finger 100F lies longitudinally above the tip 34T of the yarn guide 34 and the soft yarn emanating therefrom. The deflector 100 is relatively movable with respect to the carrier 10 in the direction of the arrow 110 from the retracted to the extended position (Figure 6) . This movement is effected prior to the first transverse of the carrier 10 across the knitting apparatus. To move the deflector an operator engages the upper edge 100E of the arm portion 100A and bends elastically this end of the deflector against its bias in the direction of the arrow 112 (Figure 2) to release the head 100H away from its abutting engagement with the surface 38U. With the head 100H cleared a longitudinally directed force (in the direction of the arrow 110, Figure 2) slides the deflector longitudinally downwardly. The sliding motion of the deflector is guided primarily by the guide pin 33P within the guide slot 100G, although the presence of the shanks of the screws 41U, 41L, assist in this function. The head 10OH of the rivet 10OR rides against the trailing side of the bracket 38.

As the lower end of the finger 100F is displaced longitudinally in the direction 110 the soft yarn S is guided into notch 100N. With the soft yarn S within the notch 100N continued relative movement of the deflector 100 deflects the soft yarn S toward the hard yarn H. The downward motion of the deflector 100 is limited by the clearance distance 104 between the guide pin 33P and the top edge of the slot 100G.

When the guide pin 33P engages the top edge of the slot further downward motion of the deflector is prohibited. In the extended position so defined (Figure 6) the lower edge 100L is substantially at the level of the tip 32T of the yarn guide 32. Thus, as soft yarn S emanates from the passage in the tip 34T of the yarn guide 34, its path is deflected by the material of the finger 100F defining the upper end of the notch 100N toward the needles of the knitting apparatus. This action has the effect of effectively diminishing the magnitudes of both the relative angle ZR (between the soft and the hard yarns) as well as the angle Zs (of the soft yarn to the line L) . The diminished values of these angles are indicated by the characters ZR , Zsa.

After completion of the first transverse pass, the deflector 100 is returned to the retracted position.

The operator catches the projecting shank of the rivet 100R (using either a fingernail or an implement) and slides the deflector is the counter direction 110' to retract the deflector.

Those skilled in the art, having the benefit of the teachings of the present invention as hereinbefore set forth, may effect modifications thereto. Any such modifications are to be encompassed within the scope of the present invention, as defined by the appended claims .

Claims

What we claim is ;

1. A carrier for conveying a first and a second yarn to a needle with an angle being defined between the yarns , the carrier comprising: a first guide member and a second guide member, each guide member having a yarn dispensing passage from the ends of which a yarn is able to be guided toward a needle, the first guide member and the second guide member being relatively movable with respect to each other in a first direction to adjust the spacing between the ends of the passages and thereby to adjust the angle between the yarns, a yarn deflector having a notch formed therein mounted for movement with respect carrier from a first, retracted, to a second, extended, position, movement of the deflector from the retracted to the extended positions causing one of the yarns to become engaged within the notch and thereby changing the magnitude of the angle between the yarns.