US3698447A - Continuous fringe cutter for fabrics woven without weft locked selvages - Google Patents

Abstract

Woven fabrics in which wefts do not form weft locked selvages but are cut off at each pick, producing uneven weft fringes, are provided with two pairs of leno warp ends, one pair on each edge, spaced apart and preferably crossing every pick. The fabric is passed against two scissor-shaped cutters which, through suitable linkage, are actuated by the lay at the end of its travel in beating up a pick. These cutters cut the fabric between the two pairs of leno ends at each edge, removing a ragged fringe. To maintain the cutters close to the inner pair of leno ends at each edge, the fabric edge contacts a vertical guide which with the cutters can move a small distance parallel to the wefts. In other words, with the guide the cutters float and are always perfectly aligned with the fabric edge.

Description

Us; 3,698,447 [451 Oct. 17, 1972 United Sttes Patent Guerin [54] CONTINUOUS FRINGE CUTTER FOR FABRICS WOVEN WITHOUT WEET Primary Examiner- Henry S. Jaudon LOCKED SELVAGES Attorney-Robert Ames Norton and Saul Leitner ABSTRACT Ernest P. GuerinQMethuen, Mass.`

[72] Inventor:

6 Claims, 6 Drawing Figures PATENTEDucr 11 |912 SHEET 1 UF 3 mvmv'ro ERNEST Fr GuERlN ATTDRNEY 1 I CONTINUOUS FRINGE CUTTER FOR FABRICS WOVEN WITHOUT WEFT LOCKED SELVAGES` BACKGROUND OF THE INVENTION pick. ln other words, there is no weft locked selvage asv in most woven fabrics. On eachedge of the fabricthere are two pairs of leno warp ends, preferably crossed atl each pick, which ends are slightly spaced apart. The type of fabric just described has many desirable properties, such as relatively soft weave, andv in many cases bulk wefts with relatively fine warp yarns, which lends the fabric to a number of special uses of considerable commercial importance.

The fabrics just described, with no weft locked selvages, have uneven long fringes on each edge where the wefts are cut after weaving each pick. The fringeis undesirable and often quite unesthetic, and it is customary to cut off the fringe between the pairs of leno ends on each edge.V Ordinarily this is done manually with shears. The result is supposed to be a fabric with very short and uniform weft ends projecting out from the inner pairs of leno ends. When the manual cutting is done accurately, an attractive, uniform edge is produced. However, there are certain drawbacks. Manual operation always increases labor costs substantially, and it is difficult to maintain perfect alignment especially when a cutter becomestired, as of course always occurs during a days run with the somewhat cramping motion of hand shears. If the manual cutting departs from a uniform distance from the inner leno' end pairs, the resulting weft ends will not be perfectly uniform, although of course they are so short that the ugly original fringe is not produced. Also, if the cutter moves his shears too far, it can occur that he will actually cut the leno ends on one or other side for a short distance, which can result in damaged or imperfect goods. Nevertheless, hand cutting` was considered necessary because with very soft weaves often produced, it is a practical impossibility to have edges at the inner pair of leno ends absolutely straight, and of course manual cutting with shears can follow such an edge even though it is not absolutely straight.

It should not be thought that the departures of the edge of the inner leno pairs from a straight line arevery gross. Often the departure from a straight line will be:

quite small, for example l/; inch or, even in the mo'st ex,

treme cases, Y; inch. Nevertheless, this is sufficient` so Y the movementof the lay in beating up each` pick. Near that if the cutting were effected with many forms of SUMMARY OF THE INVENTION In the present invention fabric with unlocked selvages and the pairs of `leno ends on each edgeA is `passed over or around a bar 'temple with a guard and held relatively taut for a short distance. At thispoint the fabric is cut with mechanical shears'having very short blades, which are actuated through linkages by the end of the lay movement it strikes the linkage andv causes the short blades to close'. In other words, the blades cut at the end of every pick, except, of course, that the location of the cutting shears is quite a few picks beyond the fell. The shortblades stay sharp for a long time and cut the wefts cleanly between the two pairs` of leno warp ends at each edge of the fabric and so can operate for long periods of time before requiring replacement or resharpening. The cuts are clean and an attractive straight edge can be produced.

` If the edges between the leno warp end pairs are quitestraight, as sometimes occurs with certain fabrics, the cutters may be in a fixedlocation crosswise of the fabric, and such an apparatus is included in the broader scope of the present invention. The short-bladedshears of course will cut a uniform line and are not subject to tiring of human cutters,'so that even in this broader `aspect an improved. fabric is obtained with much greater uniformity. However, with many fabrics havingV no weft-locked selvages, the fabric can be soft or loose, so that even when it is held accurately in a bar temple there still can be small sideways wavering. Under such circumstances and with such soft fabrics, fixed locationsz for mechanical shears can result in occasional cutting of leno ends.- Therefore, in a more preferred and more refined aspect, the cutters float, that is to say, they can move horizontally or parallel to the wefts small distances, which is effected by having a guide projectionor fence in contact with the cut edges of the fabric. This causes the cutting shears to float horizontally the smalldistances needed to follow a wavy fabric line. Of course the movement of the cutters is along a pair of guide rods or other mechanism with very low friction. As a result, even with quite soft fabrics the cutter mechanism can follow an edge accurately.

The linkage which actuates the cutter blades pulls down a rod on which the cutter blades can slide so that they can follow a not quite perfectly `straight edge. There is alittle play in the linkage and the lay is not connected to the end of the linkage but strikes it by a boss carried by the lay. The net result is that the linkage has sufficient play so that no binding will interfere with the free floating of the cutters. Itxslhould be understood This is a practical advantage as it is unnecessary to construct a new loom. This flexibility of applying the present invention to existing looms, is therefore, of practical economicadvantage.

Theoretically it is not essential that the cutting shears of the present invention be synchronized to lay motion so longas they are` actuated sufficiently frequently soA that no wefts are missed` and that the fabric does not I pile up or bind against non-moving cutter blades. ln other words, the present invention could use` an independent drive not synchronized with lay motion so long asit actuates the cutting shears at a sufficiently high frequency. However, while operative, an independent actuation involves additional expense and complication, and therefore it is greatly preferred to actuate the cutting shears by the motion of the lay itself. This eliminatesthe need for additional mechanism and accurate adjustment of linkage travel can be made by an end screwed on a threaded rod of the linkage the end striking the boss on the lay which can be adjusted accurately for the desired length of stroke at the end of lay travel. In this preferred form, therefore, the lay performs a double function, its normal one of beating up picks and actuation of the cutting shears, without requiring additional moving parts. t

The exact form of the linkage from the lay to the cutting shear blades does not, as such, constitute the distinction of the present invention from the prior art. Such linkages, often involving bell cranks and links, are well known mechanical elements and require no significant redesign in adapting them to operate the cutting blades of the present invention.

The boss on the lay in the preferred form is normally of metal, and the end of the linkage may also be of metal. However, for many operations, which will be more common in the future with growing concern for excessive noise, one or both of the contacting elements may have resilient surfaces, such as surfaces of elastomers, to reduce noise. It is still necessary, or at least highly desirable, to make the positioning of the contacts on the lay and-the end of the linkage adjustable as if the lay is still moving at the time the cutting shear blades are actuated, an unnecessary and sometimes damaging wear can result. Usually the-adjustment should be such that the lay stops accurately at the closing of the shears or slightly before. This is a matter of ordinary engineering common sense, but the modification in which one or both of the contactson the lay and the end of the-linkage are resilient makes contacts which can deform slightly and take care of any minor misadjustment. Of course means must be provided for opening the shear blades after each cut, and this is ordinarily best performed by a suitable spring, although,

vof course, any other means for opening the blades before each cut can be used. An ordinary spring is rugged, reliable and cheap and so is preferred.

Reference has beenemade to holding the fabric taut while it is being cut. One desirable and simple way is a bar temple with toothed discs which rotate, preferably discs which are mounted at a slight angle so that in moving over the bar temple there is a slight sideways stretching of the fabric. Also, a temple cap should be used to keep the fabric in contact with the temple and to prevent slippage sideways. Such a cap, which can have an opening for initial threading through of the fabric when a new batch is started, is preferably part of the whole attachment which is bolted unto the loom. The exact shape is not vital and one very simple and reliable construction will .be described belowin connection with the description of the preferred embodiments. f As the fringe is being cut continuously, it has tobe disposed of, a. simple rolling up of the cut off fringe is normally` provided. The particular disposal mechanism, as such, is not an essential feature of the present invention and any other way of disposing of the cut off fringe is included.

The present invention has been described in con-v junction with a well known type of fabric in which there are two pairs of leno warp ends on each edge of the fabric, and this is by far the most important field for the present invention. It should'be noted, however, that essentially if one analyzes the operation, there is a fabric with unlocked weft ends and locking in two narrow bands at each` edge, with cutting of the wefts in between. A somewhat similar problem results in other fabrics where wefts have loose ends at one or both edges of the fabric. Thus, for example, in a weft inserted warp knitting machine the problem is not dissimilar. Weft inserted warp knitting `machines produce a less unattractive fringe and so the problem is nowhere near as serious as with the expecially woven fabrics which constitute the most important field of the present invention. Weft insertions are frequently effected with the cutting of the inserted weft at one or both ends, and this cutting can be made more uniformly than in the particular kind of woven fabric described. In many cases the edges of a weft inserted warp knit fabric are sufficiently neat and attractive so that the present invention would not be needed, and of course in weft inserted knitting machines just as in ordinary weft locked selvage woven fabrics, if the inserted weft is not cut at each end or at one end, the present invention would not be needed at all. In the cases where the present invention would be applicable to weft inserted warp knitting machines, of course, it would be necessary to provide spacing between the knitting needles at the extreme edge and the next needles so that there would be a piece of fabric with a space sufficient to accommodate the cutting mechanism of the present invention. Also in a4 knitting machine there is ordinarily no lay and s'o other shear actuating means are needed.

BRIEF DESCRIPTION OF THE DRAWINGS F IG. l is an isometric of the front attachment;

FIG. 2 is a front elevation;

FIG. 3 is a rear elevation;

FIGS. 4 and 5 are sections along the lines 4-4 and of 5-5 of FIG. 1, the figures showing fabric in the attachment.

FIG. 6 is a plan view looking down on the table in FIGS. l, 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an isometric of an attachment with no fabric running through it, so that the elements can be clearly seen. A mounting bracket appears at l with suitable slots for mounting bolts. This mounting bracket holds a frame, with a rear member 32, best seen in FIG. 3, and a front member 33, between which there is a channel in which a flat member 34 can move for adjustment purposes. This movement of the flat rmember 34 is against spring pressure at both ends, see

FIG. 2 and 3. One of the springs is shown at 19 and fastens to a connecting link 35 with a threaded adjustment screw 36 bearing on the frame between front and rear extensions 32 and 33. This is clearly shown in FIGS. l, 2 and 3. The other end bears against a spring 37, through an extension of pivot (43), which will be described below and which can be seen in FIGS. 4 and 5.

but at the other end they are widened out and have two` openings through which pivots 38'pass and fasten these arms to the frame 33. A thirdpivot 42 fastens the arm 40 to the flat member 34, and a similar third pivot 43 performs the same function forarm 41, FIG. 1. This last pivot has an extension passing through the member 34 and contacting the end of the spring 37 as mentioned above and which is shown in FIGS. 4 and 5.

The positioning of the member 2,' which, as will be described below, carries the temple bar with cap 4, is initially set by moving the, member 34 against the spring pressure. The arms, 40 and 4l, of course, constitute a parallel linkage so that the motion of the temple bar framework 2 is,` always accurately crossways. The member 34 is moved against the two springs 19 and 37 by turning in the adjusting screw 36. The framework 2 carries Va temple bar the supporting framework3 of which is attached to the framework 2 by the bolts 44 and 49, both of which show in FIG. 1, but onlyvone, 49, can be seen in FIG. 2. In the temple bar framework 3 is mounted the temple bar proper, made up of discs 46 and plain discs 45. It revolves on an axle 47, which can be seen in FIG-S. 4 and 5. As the discs 45 and 46 are Y V u in FIG. 1. This nut performs the dual function of fastening the temple bar framework 3 to the member 2 and also supporting one end of the U-shaped rod 48 on which the cap of the bar 4 is carried. The cap extends only part of the way across so that initially fabric can readily be threaded through. It willbe noted that the cutter mechanism illustrated in the figures is for the right hand edge of thefabric looking from the fell.

Initial tilting of the cap 4 is effected by loosening the nut 49 and turning the slotted screw passing through the nut 44. When the right tilt is obtained the cap 4 is locked in position. If anything jammed between the lay and the temple bar, for example a shuttle, the bar framework 2-can move backwards a small distance on the pivots 38, 42 and 43 which cause the plate 34 to vmove sideways against the spring 19. When the obstruction is released the spring returns all the members to their original position.

FIGS. 4 and 5 show the passage of the fabric 5 over the 4bar temple and on across to a pair of shears with stationary blade 10 and movable blade 11. The shears are actuated by two rods l2, which can be seen best in FIGS. 3, 4 and 5. The rods move up a cross rod 30 which engages a fork 50 on the movable blade. The blades pivot on a pin or axle 51. Actuation of the rods 12 is effected by the lay 17, which appears broken away in FIGS. 4 and 5 and which is provided with a boss 16 contacting an end 15 of an actuating rod 14 held up by the rod 25. FIG. 4 shows the lay 17 in the position just as its boss 16 `contacts the end l5 screwed on the rod 14. As has been pointed out above, the end l5 and/or boss 16 may be of resilient material to reduce noise and to provide a slight resiliency. As the whole attachment may be moved sideways for different widths of fabric the boss 16 onl the lay may be in the form of a strip or, where the' end 15 is of resilient material the bossv 16 may be eliminated'. .i `I

As the lay moves to theleft in FIGS. 4 and 5 as shown bythe arrow, the rod 14 is pushed to the left and moves l a bell crank 52 clamped onto a shaft 53, the function of which will be described below. As the rod 14'movesto the left, the short arm 54 of the bell crank movesdown,

as indicated by the arrow on FIG. 4, and this pulls down a pin 55 on the ends of which the rods 12 are attached through their enlarged ends (FIG. 3)..3). FIGS. 4 and 5 show only one rod as it is a section, but in FIG. 3 ittcan be seen that there are infact two rods. As the rods 1,2 move down, the U-shaped'memberv 30 and legs 12 pulls the fork 50 of the movable blade 11 down. This causes the blade to rise, and it cuts through the `fabric between the two conventional leno stitchings, not shown. This position is shownin FIG. 5. A V-shaped rod 28 helps to hold the fabric tautas it approaches the cutter. As the lay then moves in the opposite direction, theblades 10 and l1 open under the influence of the spring 24, FIGS. 1 to 3, which turns the shaft 53 in the opposite direction from that just described in the movement of the shears for cutting. The spring 24 is attached to the shaft 53 by the collar 26, which is clamped tight on the shaft by the set screw 18. This is best seen in FIGS. 1 to 3. The shaft 53 extends on and has a member 22 firmly attached to its end. This member strikes a stop 23 and serves to prevent excessive movements of the blades of the shears when they are opened. The operation is best seen in FIG. 2.

The cuttersl are Vcarried by a frame moving on a Y square bar 7. This is best shown in FIGS. 1, 4 and 5. ln other words, the cutter mechanism floats and can move sideways as it also can slide along the `U-shaped member 30 which is formed bythe ends of the actuating rods 12. The floating action follows the edge of -the inner pair of leno weaves 57 and 58, FIG. 6 which bear against a fence 9, which is attached to the framework carrying the cutters by'the member 56, FIGS. 3 to 6. This fence 9 is an upturned'edge of a surface or small table 8, which can also be seen in FIG. 1. As can be u seen in FIG. 6, the fabric with the two leno weaves 57 and 58 passes over the cutters 10 and 1l, both leno weaves contacting the sides of the cutters. The fabric 5, after cutting, passes over and is supported by the table 8 as it moves across it. The cut off fringe passes down between the fence 9 and the bracket 1 and is wound on conventional disposal means, such as a reel. This disposal means is not shown on the drawings as it is conventional and does not differ 'from the fringe windup mechanisms which areused when the cutting is effected manually. In order not to obscure FIG. l, the fabric is not shown going through it but can be seen in FIGS. 4 and 5. However, as it will be seen that the section for FIGS. 4 and 5 is just behind thefence 9, and shear blades the cut fringe does not showin FIGS. 4 and 5, which only show the` fabric moving over the table 8 beyond the fence 9.

As the fence 9, table 8 and framework carrying the cutters are free to slide on the square bar 7, any depar ture from a straight line of the edge of the inner leno stitching causes the fence 9 to move slightly and maintainsthe shears at the correct point. As the mechanism, including the shears and bar 28 which holds the material taut during cutting, can move a substantial amount, for example about an inch, even quite wide variations from a straight line edge can be accommodated. In actual operation the movement of the floating shears is much less, for example from 56 inch tonot over about '/4 inch, which prevents the cutters from cutting into the leno stitching and provides a large factor of safety. The taut fabric causes the inner leno weave 57 to press firmly against the fence 9 if it wavers outwardly, and this moves both the fence and the cutters and prevents the cutters from cutting into the leno stitching 57. Slight wavering in the other direction does not move the fabric substantially out of contact with the fence 9 because the outer leno stitching 58 bears on the cutters and since they, and with them the table 8 and fence 9, slide with negligible friction on the square bar 7 there is no tendency for the leno stitching 57 to move any substantial distance away from the fence 9.

l claim:

l. In an apparatus for trimming fabric's having warp and weft elements, the wefts on at least one edge having two bands of spaced, interlocking warp ends, said wefts being cut on the outside of the outer warp end band and thus forming an irregular fringe, the improvement which comprises short blade shear means mounted to float horizontally through a small predetermined distance, said shear means being positioned to cut the wefts between the two bands of warp ends, a guide element connected to the shear means and mounted to contact the cut edge of the fabric adjacent 3. A machine according to claim 2 in whichvthe shear means are actuated through linkage contacted by and moved by the lay at the end of its motion in beating up a pick. 4

4. A machine according to claim 2 in which the loom apparatus includes a bar temple having means for stretching the fabricslightly in the weft direction and is provided with means for maintaining the fabric substantially taut during the actuation of the shear means. y 5. A machine according to claim 1 in which a lay is provided with a projecting adjustable boss and the.

shear mechanism is provided with a linkage aligned with and provided with an engaging element striking the boss on the lay during the end of the lay travel in beating up a pick.

6. A machine according to claim 5 in which at least one of said lay bossand engaging element on the linkage is of resilient material.

Il ill #Il il

Claims (6)

1. In an apparatus for trimming fabrics having warp and weft elements, the wefts on at least one edge having two bands of spaced, interlocking warp ends, said wefts being cut on the outside of the outer warp end band and thus forming an irregular fringe, the improvement which comprises short blade shear means mounted to float horizontally through a small predetermined distance, said shear means being positioned to cut the wefts between the two bands of warp ends, a guide element connected to the shear means and mounted to contact the cut edge of the fabric adjacent the inner band of warp ends, whereby the shear means are caused to follow the edge of the inner warp end band regardless of slight deviation from a perfectly straight line, means for actuating said shear means at a frequency sufficiently high that the shears cut the wefts without binding, whereby the fringe formed by the outermost band of warp ends is uniformly cut off.

2. A machine according to claim 1 in which the machine comprises a loom apparatus weaving wefts and warps and the warp end bands are pairs of leno warp ends.

3. A machine according to claim 2 in which the shear means are actuated through linkage contacted by and moved by the lay at the end of its motion in beating up a pick.

4. A machine according to claim 2 in which the loom apparatus includes a bar temple having means for stretching the fabric slightly in the weft direction and is provided with means for maintaining the fabric substantially taut during the actuation of the shear means.

5. A machine according to claim 1 in which a lay is provided with a projecting adjustable boss and the shear mechanism is provided with a linkage aligned with and provided with an engaging element striking the boss on the lay during the end of the lay travel in beating up a pick.

6. A machine according to claim 5 in which at least one of said lay boss and engaging element on the linkage is of resilient material.

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