US2820355A

US2820355A - Marker for warp knitting machines and method of marking

Info

Publication number: US2820355A
Application number: US543398A
Authority: US
Inventors: Sr Walter Hadfield; Robert D Heffelfinger; Ralph L Stimmel
Original assignee: American Viscose Corp
Current assignee: Akzo Nobel UK PLC
Priority date: 1955-10-28
Filing date: 1955-10-28
Publication date: 1958-01-21
Anticipated expiration: 1975-01-21

Description

Jan. 21, 1958 W. HADFIELD, $R,, ETAL MARKER FOR WARP KNITTING MACHINES AND METHOD OF MARKING Filed Oct. 28, 1955 MARKER FOR WARP KNETTHNG MACHINES AND METHUD F MARKING Walter Hadfield, Sn, Marcus Hook, Robert D. Heiiielfinger, Lansdowne, and Ralph L. Stimmei, Swarthrnore, Pa., assignors to American Viscose Corporation, Phila delphia, Pa., a corporation of Delaware Application October 28, 1955, Serial No. 543,398

Claims. (Cl. 66-86) This invention relates to warp knitting machines and more particularly to mechanisms for indicating and recording the relative feed of thread from two or more beams on a tricot knitting machine.

In warp knitting machines the threads are drawn from warp beams in such a manner that different lengths or feeds must be supplied in a predetermined ratio to the sley of the machine. Since the Warp beams have definite surface speeds depending upon the diameter of the thread on the beams, they must be frequently adjusted by the operator to maintain the desired predetermined ratio of thread during each cycle or rack of the machine.

The usual, but not by any means the only, cycle in such machines is one consisting of four hundred and eighty knitting movements and such cycle as well as the length of cloth produced during such cycle is generally referred to as a rack. The expression cycle of knitting movements as hereinafter used is intended to cover not only a rack of four hundred and eighty movements but any other cycle consisting of a predetermined number of such movements and is also intended to include one or more racks.

In machines of the character indicated, different lengths of thread drawn from different warp beams rotating at different surface speeds, are knitted into the same length of cloth in order to produce a certain amount of elasticity therein, and the amount of elasticity desired in a given length of cloth and the length of a cloth section or rack varies with the requirements of the customer or with the use to which the cloth is to be put. Manifestly, it is always desired to have the racks or lengths of cloth and the elastic qualities thereof uniform throughout the same web or as nearly uniform as possible, but it is diflicult to obtain such uniformity for the following reasons: The threads are drawn from the Warp beams by the knitting movements of the machine, and the Withdrawal of unequal lengths of thread is accomplished by applying difierent brake tension to the dififerent beams, in a manner well understood, so that the beams will have different surface speeds in response to the pulling action of the unwinding threads. Surface speed of the warp beams may be defined as the surface speed of the outer convolutions of the thread layers carried on the beams. At the beginning of the knitting operation, the brake tension on the several beams is therefore adjusted differently to permit the desired relative difference in surface speed and to allow different lengths of threads to be withdrawn from said beams during the knitting movements of the machine, and this difference in lengths of thread should be retained throughout the knitting of the web, if the latter is to have uniform qualities. It will be understood, however, that, as the threads are unwound, the diameters of the beams become smaller and smaller and this has to be compensated for by adjusting the tension on the beams at rather frequent intervals.

U. S. Patent 2,298,888 to Kaufmann describes a distinct rates atent II advance in the art for solving the problem of equal thread delivery in a tricot warp knitting machine. The Kaufmann disclosure, however, leaves much to be desired in that the operator must instantaneously make two observations of the running threads at points spaced at considerable distance apart and at the same time listen for a gong to ring to indicate the precise time for the visual reading. The present invention provides improved marking apparatus of the general nature disclosed by Kaufmann, but which eliminates the necessity for an operator to be at the knitting machine whenever a reading or adjustment is to be made, and also, the present invention provides a record of the relative yarn feed so that the operator can tell the precise conditions which occur at any cycle or rack and exactly how much deviation from a predetermined standard was present. Not only does the present invention provide both qualitative and quantitative results, but it enables a complete analysis to be made of the operation of the knitting machine including the determination of whether errors are compensating or cumulative. The marking ink employed may be chosen to render the record in the fabric as permanent or temporary as may be desired. Greatly improved quality and control of the knitting operation are thereby achieved.

A primary object of this invention therefore is to provide a method and apparatus for recording the relative feed of the threads from two or more beams in a tricot warp knitting machine.

A further object of the invention is to provide a plurality of marking stations in a warp knitting machine, which periodically record on the thread passing through the stations, the relative rates of travel or" said threads.

A further object of the invention is to provide in a warp knitting machine a first marking station for marking a plurality of threads, a second marking station for marking some of the threads marked in the first station, and a third marking station for marking the remainder of the threads marked in the first station.

Further objects will be apparent from the drawings and specification in which Fig. 1 is a front elevation of a part of a tricot Warp knitting machine having our improved marking device attached thereto,

Fig. 2 is an enlarged perspective detail of the first marking station shown in Fig. 1,

Fig. 3 is an enlarged perspective detail of the second marking station shown in Fig. 1,

Fig. 4 is an enlarged perspective detail of the third marking station shown in Fig. 1,

Fig. 5 is a transverse section of a part of the structure of Fig. 2, and

Fig. 6 is a fragmentary detail of the ratchet mechanism of Fig. l.

The invention comprises essentially the provision of means for guiding at least two threads from different warp beams in a knitting machine through a first marking station Where both threads are simultaneously marked by mechanism constructed and operated generally in accordance with the Kaufmann patent referred to above. From the first marking station the threads are directed to a second station spaced a predetermined distance from the first station at which one of the threads is marked for every rack. The other thread is by-passed at the second marking station. Both threads are then carried to a third marking station Where the alternate thread is marked for every rack. if the marks, which are desirably of different colored inks at the second and third stations, fall on or over the marks in the respective threads made at the first marking station, the operator knows that the tension on the warp beams is in the desired adjustment; however, if the mark at the second or third station is 3 ahead of or behind the first station mark on either thread, adjustment can be made accordingly. It is not necessary to observe the machine at the instant of marking or even once during every rack. The ink indications and their relative positions can be readily observed at a later time even after being knitted into the fabric.

Referring now more particularly to the drawings, the side frames 1d and 11 of a warp knitting machine support a cross member 12 to which a scale 13 may be attached as shown in Fig. l. A plurality of L-

shaped brackets

14, 15 and 16 are movable along the member 12 and may be clamped thereon in any desired position by means of

C clamps

17, 17. Each of the brackets Fi i-l6 contains an ink reservoir and pads Ma, 15a and 16a. The ink in pad 14a is of a different color from ink in pads 15a and Ma, whereas the color of the ink in pads 15541 and 1651 may or may not be the same. The threads X and Y are carried from upper and lower beams 19 and 2a to the first marking station designated enerally as S At this station both threads X and Y are carried through

eyelets

21, 21 in brackets 22, 22 in such a manner that they extend across and over the pad 140. The threads X and Y then proceed to the second mark ing station S where, however, the

brackets

23, 23 are slightly modified so that thread Y by-passes the pad 15a being carried in front of and below the pad as shown in Fig. 3, consequently thread X is the only thread which passes over pad 15a at S At station S the converse marking occurs due to the modified

brackets

24, 24 now by-passing thread X in back of pad 16a, and directing thread Y over and across the marking pad 16a.

A rock shaft 30 is carried across in front of member 12 and journaled at either end of the frame at 31 and 32. The rock shaft 30 is oscillated in any desired manner at periodic predetermined cycles in the running of the knit ting machine. The oscillating mechanism described in the Kaufmann patent is one of several devices for actuating this mechanism at constant predetermined intervals. A lever 33 is secured to one end of shaft 30 and is urged against a fixed stop 34 by spring 35 in Fig. 6. This position of the lever and rock shaft 3t controls the lowermost position of the various

marking arm assemblies

36, 37 and 38 at each station. In the position of the shaft in Figs. 2-6, the striker members 39, 4t] and 41 ride slightly above the threads passing over or through each station. The main shaft of the knitting machine (not shown) actuates a pawl 45 shown in Figs. 1 and 6 to periodically turn ratchet 46 in a counterclockwise direction, and holding dog 47 prevents reverse rotation of the ratchet. A pin 48 on ratchet 46 engages and advances ratchet 49 one notch per revolution of ratchet 46, and a similar holding dog 50 prevents rotation of ratchet 49. Pin 51 on ratchet 49 eventually contacts one edge of lever 33 and gradually raises the lever to turn rock shaft 30 in a clockwise direction as seen in Fig. until the pin 51 finally passes beyond the right angle contact surface of lever 33 thus permitting spring 35 to snap the rock shaft back until the lever 33 strikes pin 34. This snap action simultaneously causes the

strikers

39, 4t and 41 to mark the threads at the various stations S S S by momentarily pressing them against their respective pads 14a, a and 16a. Each of the strikers 39-41 is supported on

flexible spring arms

36a, 37a and 38a respectively to provide an instantaneous sharp contact. The spring arms 36a-38a are positioned directly under relatively

rigid damper members

36b, 37b, and 38]), which perform the important function of preventing vibration of the spring arms 36a-38a when the rock shaft snaps downwardly. This feature insures that only one impression will be made on the threads by each of the strikers 39-41. A pointer 55 may desirably be secured to the mounting collars 56 for each of the assemblies 3638 so that the strikers 39-41 may be accurately located along cross member 12 by means of scale 13.

In operation, the marking stations are set along member 12 in accordance with the predetermined desired relative feed of threads X and Y. In the setting shown in Fig. 1, thread Y feeds approximately 64 inches, while thread X feeds approximately 48 inches per rack. At the instant both threads X and Y are marked at station S the marks on each thread of course will be aligned. At the end of one rack the marks placed on each thread at station S for example blue marks B, B. will have travelled different distances to their respective stations S S if the knitting machine is properly adjusted. At any event, at the end of one rack the thread X is marked at station S by a red mark, for example R. If the red mark R falls directly over the blue mark B on thread X, this thread has, in the present example, travelled exaetly 48 inches in one rack as desired. However, if the red mark R is slightly in advance of the blue mark B, as shown in Fig. 3, thread X is travelling too slowly and suitable adjustment on the beam mechanism is indicated. Similarly at station 8 the blue mark B on thread Y will be directly under the marking edge 41 if thread Y travels 64 inches in one rack. Assuming that the machine is at the proper desired adjustment, the red mark R falls directly over the blue mark B, as shown for both threads in Fig. 4. It will be understood that the width of one marking element may be made slightly wider than the other if desired although an experienced operator can readily tell whether or not the marks are superimposed. In the drawing it has been indicated that one mark is wider than the other, however, such an expedient is not necessary in practice.

The present invention greatly improves the quality of tricot fabrics since it provides an extremely accurate indicator and recording mechanism for determining the rate of thread feed. The actuating pawl 45 may be disengaged so that the recording device does not have to be used at all times. However, for accurate quality control it may be desirable to record the feed for an entire run of fabric to determine whether the variations in feed eventually compensate or whether feeding speed differences gradually cumulate.

Having thus described our invention, we claim:

1. The method of permanently recording the relative feed of warp threads in a tricot warp knitting machine which comprises the steps of feeding a plurality of knitting threads to a first marking station, simultaneously marking each thread at said first station, feeding each of said threads to second and third marking stations at different speeds, said second and third marking stations being spaced from said first marking station predetermined distances different in length, and simultaneously marking alternate threads at said second and third stations.

2. The method of recording the relative feed of warp threads in a tricot warp knitting machine which comprises feeding at least one thread from an upper warp beam of the knitting machine to a first marking station, feeding at least one thread from a lower warp beam of the knitting machine to said first marking station, said threads being fed from their respective beams at different speeds, directing one of said threads to a second marking station spaced from said first marking station a distance equal to the length of said one thread which is to be supplied during a predetermined cycle of knitting movements, directing the other of said threads to a third marking station spaced from said first marking station a distance equal to the length of said other thread which is to be supplied during the same predetermined cycle of knitting movements, and simultaneously marking both threads at the first station, one thread at the second station, and the other thread at the third station.

3. In warp knitting apparatus the combination which comprises a cross member positioned in front of the knitting machine frame, a marking device at one end of said cross member, means for directing a plurality of warp threads across said marking device, a second marking device adjustable along said cross member and mounted in spaced relation to said first marking device, means for directing one of said threads across said second marking device, a third marking device adjustable along said cross member and mounted in spaced relation to said first and second marking devices, means for directing the other of said threads across the third marking device, and means for simultaneously marking both threads at the first marking device and alternate threads at the second and third marking devices.

4. Apparatus in accordance with claim 3 in which the color of the markings applied at the first marking device are in contrast to the color of the markings applied at the second and third marking devices.

5. Apparatus in accordance with claim 3 in which the simultaneous marking means comprises a rock shaft, a resiliently mounted striker on said rock shaft for each of the marking devices, and means driven by the knitting machine shaft for snapping the rock shaft about its axis to cause the strikers to contact the threads.

6. In warp knitting apparatus the combination which comprises a cross member in front of the knitting machine frame, a bracket adjustably secured at one end of sa d member, an ink pad on said bracket, means for directing a plurality of threads across the face of said pad, a second bracket slidably secured to said member, an ink pad on said second bracket, means for directing one of said threads across said pad in the second bracket, 21 third bracket slidably secured to said member, an ink pad in said third bracket, means for guiding the other of said threads across the pad in said third bracket, a rock shaft journaled in spaced relation to said member, means associated with the knitting machine for map ping the rock shaft about its axis at a predetermined point in the cycle of the knitting machine, and marking elements resiliently mounted on said rock shaft for pressing the threads against the ink pads when the rock shaft is snapped.

7. Apparatus in accordance with claim 6 in which the first mentioned ink pad contains an ink differing in color from that contained by the second and third mentioned pads.

8. Apparatus in accordance with claim 6 in which the marking elements are provided with relatively rigid dampering means.

9. A marking device for warp knitting machines comprising a horizontal cross member, a bracket slidably mounted on said cross member, means including a clamp for securing the bracket to the cross member at adjusted horizontal position, an ink pad in said bracket, side plates on said ink pad, and eyelets on each of said side plates for directing only one of a plurality of threads across and over said ink pad.

10. In warp knitting apparatus the combination which comprises a cross member positioned in front of the knitting machine frame, a marking device at one end of said cross member, means for directing a plurality of warp threads across said marking device, at least one other marking device adjustably mounted along said cross member in spaced relation to said first mentioned marking device, means for directing one of said threads across said second mentioned marking device and means for simultaneously marking said threads at said first and second marking devices.

References Cited in the file of this patent UNITED STATES PATENTS 2,298,888 Kaufmann Oct. 13, 1942