US1970528A - Drawing mechanism for spinning frames and similar machines - Google Patents

Description

Aug. 14, 1934. R. D. TARR El AL DRAWING MECHANISM FOR SPINNING FRAMES AND SIMILAR MACHINES Filed Feb. 29. 1932 Patented Aug. 14,1934 I I I I UNITED STATES PATENT OFFICE DRAWING MECHANISM ron SPINNING FRAMES AND SIMILAR MACHINES Roderic D. Tar-r, Biddeford, and Edmund E. Blake, Saco, Maine, assignors to Saco-Lowell Shops, Boston, Mass., acorporation of Massachusetts Application February 29, 1932, Serial No. 59537 6 Claims. (01. 19-131) This invention relates to drawing mechanisms 21 rests on the belt immediately above the for spinning frames and similar machines. It bar 12. is more especially concerned with mechanisms The mechanism so far described may be, and 1 of this type used in what is known as long preferably is, substantially like that shown and 5 draft spinning frames, the best example of described in the patent above referred to. The

which is shown in United States Letters Patent sliver is led through the rolls in succession, the No. 1,804,968, dated, May 12, 1931, preparation draft being applied to it between Long draft spinning has been known t limthe rear rolls 8 and 9 and the intermediate rolls ited extent for many years, but the invention 6 and 7, and it is then subjected to a main draft to disclosed in t patent above mentioned h between the intermediate'and the front rolls.

for the first time made long draft spinning in. The lower intermediate knurled roll 6 drives able in a commercially satisfactory form. The the belt apron 10 and the T011 14 is made of mechanism shown i aid patent h t suflicient mass or weight to keep the belt taut. very extensive use and has been exceptionally In the arrangement heretofore used this belt 7 iii successful, I tensioning roll 14 has been guided to swing about It is the chief object of the present invention the axis of a rod 16, 4, which'has been further to improve mechai'iisms cf t general located in approximately the relationship to the type show i th patent, above designated with belt and the roll 14 shown in said figure, and the a view to making them even more reliable. guiding d vi e s be n a ra ed to maintain $.36 The nat of th invention will be readily the axis of the belt tensioning roll at a constant understood from the following description when distance from the axis of the rod 16 and 0011- read in c nn ti t t accompanying drawstantly parallel also to the axis of the driving ing, and the no l feature w be particuiafly roll 6. It has been the usual custom; also, to pointed out in th appended claims. make these belts of leather, calfskin being very I th drawing commonly employed, and whether made of this Figure 1 is a r elevation of a drawing material or not it has been necessary to cut mechanism similar t t t shown in the patent them out of sheet material and to cement the above designated, b t modified in accordance ends together so as to make an endless belt. with the present inv ti It occasionally happens that a belt will not be Fi 2 i vertical, Sectional View approxi; cut or cemented exactly straight so. that one mately on the li 2-2, Fig 1, but indicating side or margin of the belt will be slightly longer the clearer roll i place; than the other, or one margin of the belt may Fig. 3 is a diagrammatic view illustrating stretch more than the other after it has been tain features of the mechanism shown in Figs. use for a timewhen any Substantial 35 i and 2; and ference in thelengths of the two margins of Fig, 4 i view similar to 3 but showing the belt occurs, it has been found that the belt the prior art arrangement, crowds against one flange of the roll 14 and The drawin mechanism Shown in Figs 1' 2 curls over, thus producing after a time an l ne and 3 comprises a roll stand 2 having suitable satisfactory operating condition- While this an hearings i hi h th c driven 1 4, 6 d does not occur very frequently and the crooked a, respectively are mounted Upper rolls 5 7 belts can be removed and replaced, nevertheless and 9 cooperate with the respective r0118 4, 6 this condition is not satisfactory. To devise an and 8 to form three pairs of rolls, namely, front effective PP for h problem a by rolls 4 and 5, middle or intermediate rolls 6 and these FOndItEODS constltutes the chief ObJect and back rolls 8 and 9. Usually the lower 9f the mYentlon I front and rear rolls are fitted or grooved while A conslderame Ya-nety of anal-lge-ments haYe the lower middle roll 6 is knurled. Usually also been-used for belt-tensmmng Ions m H 113 9 leather 0 r d A It drawing mechamsms 1n WhlOh endless be1ts or 1' upper m ar C Y e e aprons are employed, but all of them of winch f 10 Passes between the mteFmedlate rolls we have been able to learn are objectionable e and '7, runs w d v a statwnary bar 12, because of the action above described. A careand then extefldsj downwardly a rearwardly' ful analysis ofthe causes responsible for this a u d a 0 1 14 w l h is provid d result and exhaustive experiments indicate that a with end flanges to limit the lateral movement the difliculty is caused in some cases, as for @f the belt relatively to the r011- A p roll example in the arrangement above described,

by an'action between the belt tensioning'roll and the belt, similar to thatwhich occurs in a crowned pulley. Inoth'er' cases the underlying cause appears to beat; slight twisting action exerted on the beltby the tensioning pulley due to the fact that the axis of the pulley gets out of alinement with the axis of the driving roll.

We have found that these difliculties can be avoided by splitting the guide shown in the patent above designated for the belt tensioning roll so as to permit the two arms of the guide to swing independently of each other, and by so mounting these guiding arms that the axis of the roll 14 will be held approximately in a plane passing through the axis of the driving roll 6 notwithstanding differences which ordinarily are found, and must be reasonably expected, in the lengths of the two margins of the belt 10.

Referring to Figs. 1 and 2 it will be seen that the opposite projecting ends of gudgeons of the belt tensioning roll 14 are guided by swinging arms 15-15 both mounted on the rod 16 which is supported in parts of the stands 2. Also, that the location of this rod has been changed as compared to the arrangement shown in Fig. 4, and that it occupies such a position that the arms 15-15 guide the roll 14 for belt tensioning movement in a plane passing through the axis of the driving roll 6. In other words, the arms 1515.permit the tensioning roll to take any position required to maintain the tension on both margins of the belt approximately equal, notwithstanding differences in the lengths of said margins, while at the same time so guiding the two gudgeons of said roll as to maintain the axis of the roll approximately in a plane extending through the axis of the driving roll. With this arrangement, therefore, the tensioning roll may assume various angular relationships to the driving roll, its axis either being parallel to the axis of the latter roll or not, but the axes of the two rolls always lie approximately in the same plane. This arrangement has been found to operate highly satisfactorily.

In an ideal arrangement the plane connecting the axes of the roll 14 and rod 16 would lie at right angles to the plane connecting the axes of the rolls 6 and 14. Considerations of economy, however, and the necessity for avoiding interference with the removal of the clearer roll 3'7 from the machine and its replacement therein, make it preferable to locate the rod 16 approximately as shown in Fig. 2, so that the plane connecting the axes of the roll 14 and the rod 16 are not quite perpendicular to the plane through the axes of the rolls 14 and 6. However, the relationship is so close to the ideal arrangement above described that the practical effect is the same, and the belt is guided without any appreciable tendency to crowd endwise of the roll 14 notwithstanding substantial differences in the lengths of the two margins of the belt.

The difierences in the belt tensioning movement produced with the present arrangement as compared to a typical prior art construction is illustrated in dotted lines in. Figs. 3 and 4, although'the extreme range of movement of the belt is somewhat exaggerated in proportion to the other elements. In practice a difference in the length of one-quarter of an inch in the two margins of the belt would represent what might belt tensioning roll, however, is so supported that its opposite ends can drop independently of each other into positions determined solely by the operating lengths of the two margins of the belt. At the same time any twisting of the belt is prevented and the guiding arrangement is such that approximately the entire weight of the roll is efiective to tension the belt.

The arms 15-15 are held properly spaced from each other and in correct lateral positions by means of spring clips 20 which are snapped over and grip the rod 16 and which bear lightly against the sides of the guiding arms.

The invention thus improves in a very simple and inexpensive way the running conditions in a drafting mechanism of the type above described, and completely avoids a difliculty which has been annoying heretofore. It also avoids the presence of any surfaces on which the tensioning roll can climb due to its rotation and thus move out of its proper running position. This has been an objectionable feature of some of the prior art constructions.

A further advantage of this construction is that it results in a more uniform and better cleaning of the belt 10 by the clearer roll or scavenger roll 3'7. A customary arrangement is to provide a single clearer roll running in contact with all of the belts 10 of a series of adjacent drafting units, the roll 37 also bearing lightly against the lower rear rolls 8. Such a clearer roll has gudgeons at its opposite ends which are supported in springs and one of these springs is shown in Fig. 2 at 38. Consequently, the clearer roll is maintained yieldingly ina fixed position and it is revolved slowly by its contact with the rolls 8 and belts 10. In the arrangements heretofore employed, if one of 'the belts stretched more than the others it allowed its belt tensioning roll to drop away from the clearer roll 3'7and resulted either in moving the belt out of contact with the clearer roll, or in reducing the pressure of the belt against the clearer'roll, with a consequent tendency to reduce the cleaning actionof the clearer on the belt. On the other hand, if one side of any belt stretched more than the other, the resulting twisting action which would be produced in this manner, as above described, would tend to move the longer margin of the belt away from the clearer roll and might either actually produce this result, or so reduce the pressure against the clearer roll that this part of the belt could not be properly cleaned.

The present arrangement overcomes both of these difliculties due to the fact that it maintains the taut sides of all the belts of adjacent units constantly in substantially the same plane notwithstanding variations in the lengths of the belts or differences in the lengths of the two margins of an individual belt. Each drafting unit, therefore,' is kept constantly in a better and more uniform condition than has been pos sible with prior arrangements.

While we have herein shown and described a preferred embodiment of our invention, it will be evident that the'invention may be embodied in other forms without departing from the spirit or scope thereof.

Having thus described our invention, what we desire to claim as new is: I

1. In a drawing mechanism of the type in which an endless belt cooperates with additional .devices to grip the roving or sliver during thedrawing operation, the combination of a driving also obtaining substantially all of the belt tensioning eflect oi the latter roll.

2. In a drawing mechanism of the type in which an endless belt cooperates with additional devices to grip the roving or sliver during the drawing operation, the combination of adriving roll for said belt, a belt tensioning roll supported by said belt, two pivoted arms for engaging and guiding opposite ends of said belt tensioning roll, and means for supporting said arms for swinging movement independently of each other about a fixed axis.

3. In a drawing mechanism of the type in which an endless belt cooperates with additional devices to grip the roving or sliver during the drawing operation, the combination of a driving roll for said belt, a belt tensioning roll supported by said belt two pivotedanns for engaging and guiding opposite ends of said belt tensioning roll, and means i'or supporting said arms for swinging movement independently of each other about anaxis positioned to cause said arms to maintain the axis oi said belt tensioning roll approximately in a plane extending through both said axis and the axis of said driving roll notwithstanding normal differences in the lengths of opposite margins of said belt.

4. In a drawing mechanism 01' the type in which an endless belt cooperates with additional devices to grip the roving or sliver during the drawing operation, the combination of a driving roll for said belt, a roll supported by said belt for tensioning the belt. swinging guides for the opposite ends of said belt tensioning roll arranged to allow the two ends of the latter tional devices to grip the roving or sliver during the drawing operation, the combination of a driving roll for said belt, a roll supported by said belt for tensioning the belt, and swinging guides tor the opposite ends of said tensioning roll arranged to maintain the axis oi the latter roll approximately in a plane extendingthrough the axes of both of said rolls while enabling the opposite ends of the belt tensioning roll to rise and fall independently of each other due to its own weight to cause said roll to equalize the tension on both margins of the belt notwithstanding diflferences in the lengths of said margins, and means supporting said guides for in: dependent swinging movement.

6. In a drawing mechanism of the type in which an endless belt cooperates with additional devices to grip the roving or silver during.

the drawing operation, the combination of a driving roll for said belt, a belt tensioning roll supported by said belt, two pivoted arms for engaging and guiding opposite ends of said belt tensioning roll, and means tor supporting said arms for swinging movement independently of each other about an axis located behind and above the axis of said belt tensioning roll.

nonmuc D. TARR. EDMUND a. slim.

no I

Images