US3604195A - Drafting apparatus - Google Patents

Abstract

An apparatus to stop the supply of roving to a drafting system when an end breaks to prevent lap damage to the drafting system by physically rotating a stop member into the path of flow of the roving supply.

Description

United States Patent Inventors Grady H. Sanders;

Robert M. Ingham, Jr., both of Spartanburg, S.C.

Appl. No. 838,212

Filed July 1, 1969 Patented Sept. 14, 1971 Assignee Deering Millikan Research Corporation Spartanburg, S.C.

DRAFTING APPARATUS 5 Claims, 5 Drawing Figs.

19/255 Int. ("I D0lh 13/18 Field of Search 19/126,

References Cited UNITED STATES PATENTS Tabor Tolman et a1. Rhoades Campbell Holmes Henry Walsh Oswald Primary Examiner-Dorsey Newton Atlomeys-Norman C. Armitage and H. William Petry l9/.26 57/84 57/87 57/87 l9/.26 l9/.26 19/253 X 19/283 ABSTRACT: An apparatus to stop the supply of roving to a drafting system when an end breaks to prevent lap damage to the drafting system by physically rotating a stop member into the path of flow of the roving supply.

PATENTED SEP] 4 I97! SHEET 1 OF 2 INVENTORS SA N D E R S M.|NGHAM,JR.

ATTORNEY PATENIEU SEPI4I97I I SL604; 195

SHEET 2 0F 2 40 A 1' 2m 54 so a I l 24 g 1 80 E 74 7o 84 I 9 7 84 72 INVENTORS GRADY H. SANDERS ROBERT M.INGHAM,JR. BY

ATTORNEY DRAFTING APPARATUS This invention relates generally to drafting systems for spinning frames and in particular in the prevention of lap damage to a drafting system when an undetected yearn break occurs between the ring rail and the front rolls of the drafting system.

When drafting roving or sliver prior to spinning into yarn very often a break will occur between the rear drafting rolls and the ring and traveler of the spinning frame. Normally, the break will occur between the front drafting rolls-and the ring and traveler of the spinning frame. When this condition happens the roving or sliver being supplied to the drafting system will continue to be supplied to the front rolls causing the roving or sliver to wrap around the front rolls and then pile up between the front and middle drafting rolls. This pileup of fibers between the rolls can cause the aprons to freeze and be torn up by the rotating rolls. This condition is very severe on the lower drafting apron since the middle lower drafting roll is normally knurled which chews up the inside of the apron. If the condition occurs very often it causes a lot of inconvenience since only a limited number of spare aprons are available on the lower rolls and when these are exhausted it is necessary to use spliced aprons which are ineflicient in operation, thereby lowering the spinning frame efficiency and the yarn quality. Further, if there is a large buildup of fibers between the rolls, there will be a tendency for the drafting cradle to be broken and thereby not only require replacing of the cradle but also resulting in the destruction of both the drafting aprons.

It is therefore an object of the invention to provide a method and apparatus to prevent lap damage to a drafting system.

Another object of the invention is to provide a lap damage the roving or sliver being supplied to a drafting system when a break occurs in the fiber being drafted and/or spun.

A still further object of the invention is to provide a roving stop system which is sensitive to a lap up on either the top or bottom front roll of a drafting system.

Other objects and advantages of the invention will become readily apparent as the specification proceeds to describe the invention with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a drafting system in normal position and incorporating the herein disclosed invention;

FIG. 2 is a view similar to FIG. 1 illustrating the condition of the drafting system when an end break occurs;

FIG. 3 is a bottom view of two drafting positions showing normal operating positions of the lap-up detector;

FIG. 4 is a blown-up perspective view of the new and improved roving stop incorporated in the drafting system of FIGS. I3;and '7 FIG. 5 is a blown-up view of the new and improved cradle employed in the drafting systems of FIGS. l-3.

Looking now to the drawings, FIG. 1 showsthe improved drafting system in conventional operation with a roving or sliver of staple fibers passing through a condenser, supported by elongated bar 13, into the nip of upper and lower rear drafting rolls l4 and 16, middle drafting rolls l8 and 20, front drafting rolls 22 and 24 to a ring and traveler (not shown) to form yarn Y by placing twist therein between the ring and traveler and the nip of front drafting rolls 22 and 24. Conventionally, top drafting rolls l4 and 22 are rubber covered rolls while intermediate top drafting roll 18 is knurled. Bottom front and rear drafting rolls 24 and 16 are fluted rolls while the middle bottom roll is knurled.

Inasmuch as the major amount of drafting is conventionally accomplished in the zone between the middle rolls 18, 20 and the front rolls 22, 24 from which the fibers proceed and are either twisted into yarn or drafted further, and since the running mass of fibers is also brought into a minimum size in the zone between the middle and front pair of rollsfit is most preventer for a drafting systemwhich will stop the delivery of desirable that the fibers be controlled as closely as possible and to this purpose a double-apron system, consisting of upper endless apron 26 and lower endless apron 28, is used. In a manner exemplified in the art, e.g., US. Pat. No. 3,386,]36, upper and lower apron clearing and roll engaging members 30 and 31 connected to cradle 32 are supported within the aprons 26 and 28 and at one end have a concave surface 34 engaging the rolls to clean the peripheral surface thereof and at the other end an apron reversing nose portion. Cradle 32, which has two upstanding wall members 38, has a conventional roving shelf secured therebetween to guide the roving into the nip of the drafting rolls and between the middle and back rolls, thereby preventing a lap up due to improper feed of the roving into the drafting system.

Looking at FIG. 5, the cradle 32 is shown in detail. Cradle 32 preferably is made from a material which is readily moldable and has good stability and wear characteristics such as for instance, Delrin acetal resin, nylon or Bakelite. Notches 42 in the sidewalls 38 are of sufficient size to accommodate the lower middle roll 28 while notches notches 44 in the sidewalls 38 are larger than the supporting shaft 45 of the upper roll 18 for reasons hereinafter explained. Lower apron clearing member 31 is hollow and telescopes over hollow projections (not shown) molded to sidewalls 38 and is secured in such position by fingers which are integral with bar member 52 and engage the outsides of roving bar receptacles 54 to urge Walls 38 toward one another. A notch 56 is provided in each of the cradle sidewalls 38 to allow circular tab projections 58 on the upper apron clearing member 30 to slide therein to position member 30. Tabs 58 in conjunction with apron 26 positions the member 30 in operative position against the upper drafting roll 18.

FIG. 4 shows in detail the roving stop 60 which, as shown in FIGS. 1-3, extends across two drafting positions and encircles a portion of the diameters of lower back rolls 16. The roving stop 60, like the cradle 32, is made from a readily moldable material which has good stability and wear characteristics. The roving stop 60 is circular in shape and has a diameter slightly less than the diameter of rolls 16. The edge of the rev ing stop 60 adjacent to the incoming roving is thinner than the opposite edge to provide for ease of movement into the nip of rolls 14 and 16. Also the edges 62 are higher than the edges 64 to allow only a small portion of the stop 60'to enter the nip of rolls l4 and 16 initially. Molded to the bottom of the roving stop 60 is an elongated roving stop portion 66, which can have a serrated edge, if desired, and functions upon the occurrence of an ends down to bite into the roving 10 as hereinafter described. Also, preferably molded to the roving to the stop 60 are tabs 68 which are engaged by hook members 70 to prevent the roving stop 60 from rotating with the rolls 16 in normal operation. A further tab member 72 is provided to engage the trumpet support 13 when the roving stop 60 is actuated to limit the rotational movement of the roving stop 60. A truncated projection 74 is also provided to aid an operation in resetting the roving stop 60 after it has been actuated.

Mounted on the roll shaft on boss 46 of the lower middle rolls, between two adjacent drafting positions is the roving stop actuation mechanism, generally designated 76. Basically, the mechanism consists of elongated side members 78 and 80 which span the three roll positions and have a notch 82 therein which engages the shaft or boss 46. The wall members are secured together by cross-connecting bars 84. Preferably, the mechanism 76 will be molded from a readily moldable material which has goodrstability and wear characteristics and in which case the crossbars 84 will be integral with the wall mem-' bers.

Looking now in more detail at FIG. 1 and 2, the drafting system is shown in the operative and inoperative positions, respectively. In FIG. 1, the mechanism 76 is so positioned that the hook portion 70 at one end engages the tab 68 to prevent the rotation of the roving stop 60 with the roll 16 and the finger portion 86 at the other end is riding on the boss 88 between the upper front drafting rolls 22.

Looking now to FIG. 2, the action of the cradle assembly is illustrated when the yarn end 90 breaks. Since the yarn end between the nip of the front rolls 22 and 24 is broken and roving is still being supplied, the roving will tend to lap around the bottom roll and build up in the area between the nip of the front rolls and the nose portions of the apron. As the lap 92 increases in diameter it will contact the apron 28 causing the cradle to rotate clockwise around the rolls 18 and 20. This is accomplished since the notches 56 in the cradle sidewalls allow the tabs 58 to move forward as the cradle rotates and the upper roll 18 does not restrict such movement.

At the same time the roll 22 will move upwardly thereby moving the finger portion 86 in the clockwise direction causing the roving stop actuation mechanism 76 to pivot in a clockwise direction around the shaft or boss 46 of the middle lower roll 20. When the lap 92 has built up to a certain point, the roving stop actuation mechanism 76 will have rotated to a point when the hook portion 70 thereof is disengaged from the tabs 68 on the roving stop 60 thereby allowing the roving stop 60 to rotate with the lower rear roll 16 until the triangularshaped roving stop portion 66 bites into the roving l and prevents further delivery of the roving into the nip of rolls l4 and 16 thereby preventing further buildup of the lap 92.

A bottom roll lap has been described above but essentially the same action will occur if the lap builds up on the top roll except that the cradle will not be rotated. It is obvious that the buildup of a lap on the top roll 22 will push the finger portion 86 upwardly to pivot the roving stop actuation mechanism and release the roving stop 60.

As discussed previously, the roving stop member has a tab 72 thereon which contacts the trumpet support 13. This tab 72 basically is to prevent the further rotation of the roving stop 60 when the top rolls l4, l8 and 22 have been lifted in order to remove the lap and place the drafting system back in operation.

The herein improved system provides a drafting apparatus which will not normally be damaged if a lap builds up on either of the front drafting rolls. Further, such apparatus will automatically cut off the supply of roving to the drafting upon the occurrence of the formation of a lap on either of the front drafting rolls.

Although we have described in detail the preferred embodiment of the invention, we contemplate that many changes may be made without departing from the scope or spirit of the invention and we desire to be limited only by the claims.

That which is claimed is:

l. A drafting system comprising: at least three pairs of drafting rolls spaced from one another in operative relationship, each of said pairs of drafting rolls being in nip forming relationship, an arcuate-shaped fiber stop means partially encircling one roll of one pair of rolls, said fiber stop means having a portion thereof adapted to rotate into the nip of the roll on which it partially encircles and means mounted on one roll of a second pair of rolls of said three pairs of rolls and including a first portion operably associated with the top roll of a third pair'of rolls for sensing the upward movement thereof and a second portion engaging said fiber stop means to prevent said fiber stop means from rotating with the roll on which it is mounted and to release and allow said fiber stop means to rotate with the roll on which it is mounted to place said portion in the nip of said one pair of rolls upon sensing the upward movement of said top roll of said third pair of rolls due to a lap on either roll of said third pair of rolls.

2. The structure of claim 1 wherein said second portion of said means includes a hook portion engaging said stop means during normal operation of said drafting system.

3. The structure of claim 2 wherein said stop means is mounted on the bottom roll of said first pair of rolls.

4. The structure of claim 3 wherein said means is pivotally mounted on the bottom roll of said second pair of rolls.

5. The drafting system of claim 1 wherein a second set of three pairs of rolls is provided spaced from the first set of three pairs of rolls and said means mounted on one roll of a second pair of rolls is located between the two sets of rolls.

Claims (5)

1. A drafting system comprising: at least three pairs of drafting rolls spaced from one another in operative relationship, each of said pairs of drafting rolls being in nip forming relationship, an arcuate-shaped fiber stop means partially encircling one roll of one pair of rolls, said fiber stop means having a portion thereof adapted to rotate into the nip of the roll on which it partially encircles and means mounted on one roll of a second pair of rolls of said three pairs of rolls and including a first portion operably associated with the top roll of a third pair of rolls for sensing the upward movement thereof and a second portion engaging said fiber stop means to prevent said fiber stop means from rotating with the roll on which it is mounted and to release and allow said fiber stop means to rotate with the roll on which it is mounted to place said portion in the nip of said one pair of rolls upon sensing the upward movement of said top roll of said third pair of rolls due to a lap on either roll of said third pair of rolls.

2. The structure of claim 1 wherein said second portion of said means includes a hook portion engaging said stop means during normal operation of said drafting system.

3. The structure of claim 2 wherein said stop means is mounted on the bottom roll of said first pair of rolls.

4. The structure of claim 3 wherein said means is pivotally mounted on the bottom roll of said second pair of rolls.

5. The drafting system of claim 1 wherein a second set of three pairs of rolls is provided spaced from the first set of three pairs of rolls and said means mounted on one roll of a second pair of rolls is located between the two sets of rolls.

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