Title of Invention

A DRIVE APPARATUS FOR THE DETACHING ROLLERS OF A COMBING MACHINE

Abstract

The invention relates to a drive apparatus for detaching rollers (23) in a combing machine with a differential gear (21) whose one primary shaft is connected with a drive imparting the primary shaft with an even rotational movement and whose other primary shaft is connected with a control apparatus imparting an additional rotational movement, with an eccentric (8) held on the frame, which eccentric is connected via a drawbar (10) with a crank (A, E) which imparts the eccentric with an uneven rotational movement of constant drive speed and is held in a manner as to be offset from the point of rotation (B) of the eccentric, with the eccentric (8) bearing a rocker (11) which is supported at a circumferential point (J) in an articulated manner on a supporting lever (14) which is rotatably held on the frame, which rocker, for the transmission of a movement imparted to it by the eccentric, is connected by way of a connecting rod (16) with a control lever (17) of the said other primary shaft (20) for the additional rotational movement. With the known apparatus a limit had been reached whereby the increase of the nip counts was no longer possible without causing problems. On the basis of the known design a special design is proposed for increasing the nip count, with the ratio of the distance between the point of articulation (D) of the drawbar (10) on the eccentric (8) and its point of rotation (B) to the distance between the centre (C) of the rocker (11) and the point of rotation (B) of the eccentric (8) being chosen larger than 3.5.

Full Text

The invention relates to a drive apparatus for the detaching rollers of a combing machine in accordance with the preamble of claim 1. During the combing process of a combing machine the end of a lap projecting from a nipper unit (hereinafter referred to as a "fibre tuft") is combed out by a combing segment of a circular comb rotatably held underneath the nipper. The nipper unit is held in such a way that it can perform an oscillating movement. The nipper is closed in its rear position where the combing of the fibre tuft is performed. During the forward movement of the nipper in the direction towards a rotatably held pair of detaching rollers the nipper opens and the end of the projecting and combed fibre tuft is placed on the end of a fibre fleece projecting from the detaching rollers. During this process the fibre tuft reaches the area of action of a top comb. The pair of detaching rollers performs a pilgrim step movement during the nip of the comb and is coupled with respective drive devices in order to perform this movement. Once the end of the fibre tuft projecting from the nipper rests on the end of fibre fleece which is partly conveyed back by the detaching rollers, the detaching rollers will perform a reversing movement. In this process the fibre tuft end is entrained and reaches the nip point of the detaching rollers. During the further rotational movement of the detaching rollers a fibre package on the lap end is pulled out from the lap projecting from the nipper and pieced (or joined) together with the end of the fieece. The extracted fibre package has been pulled through a row of needles of a top comb, thus further removing short fibres, neps and other impurities in addition to the combing work provided by the circular comb. Once the detached fibre package has been pieced together with the end of the fleece the direction of rotation of the detaching cylinders is reversed again and the newly formed end of the fleece is displaced again by a partial amount in the direction towards the nipper unit for the next piecing process. The literature „Die Kurzstapelspinnerei" (Short Staple Spinning) - W.Klein; Vol. 3 of The Textile Institute (ISBN 3-908.059-01-1) shows on page 31 the interaction of the sequence of movements of the nipper, detaching rollers and combing units in a graphical illustration. Pages 8 to 10 explain the sequence during the nip of the comb in closer detail. CH-PS 499 635 discloses a mechanical drive device for performing the pilgrim step movement for the detaching rollers which is still used in this form in current combing machines and performs up to 350 nips per minute (n.p.m.). There is a demand to increase the performance and thus the nip count of the combing machine. With the gear as shown in CH-PS 499 635 a limit was reached with the current design where the required accelerations of the detaching rollers to perform the pilgrim step movement would no longer mechanically allow any increase of the nip count, which means that in the event of any increase of the forces of acceleration the mechanical stresses (in particular for the bearings of the mechanical elements) would have become too high. In addition, the noise would have risen to an excessive level. To solve this problem efforts were made to replace the purely mechanical drive by an electromotive single drive. Such a solution has been described in EP-PS 374 723 for example. It has been seen, however, that although this type of drive provides a number of benefits concerning the possibilities for adjustment, very powerful motors are required in the case of an increase of the nip count, which on the one hand are relatively expensive and on the other hand require complex control systems in order to ensure synchronous running with the other elements involved in the combing process. Current increases in the nip count with the solution which has been known since 1971 through CH-PS 499 635 could be achieved particularly by reducing the masses of individual elements such as the nipper, the detaching cylinders, etc. However, according to the current level of knowledge a limit has been reached which no longer allows any further reduction of masses without losing mechanical strength properties. It is the object of the present invention to find a solution to increase the nip count and thus the performance of the combing machine which on the one hand is reliable and on the other hand inexpensive. Since with the currently used, purely mechanical solution (CH-PS 499 635) one already has a reliable solution that is used all over the world, efforts were made to find a solution on this basis which enables an increase in performance. Through numerous computer simulations and calculations it was found that in a specific design of ratios of lever lengths in the area of the eccentric it is possible to reduce the acceleration of the detaching rollers even with an increase of the nip count. This means that by a purposeful selection of lever lengths in relationship to one another it has been managed to increase the performance of the machine and thus the nip count on the basis of the currently proven system. In order to solve the problem it is now proposed that the ratio of the distance between the point of articulation of the drawbar on the eccentric and its point of rotation to the distance between the centre of the rocker and the point of rotation of the eccentric is chosen larger than 3.5. The drive area in the eccentric with the lever lengths of the rocker to the subsequent connecting rod and control lever and the drawbar acts like an amplifying member for the optimal transmission of the drive force under adherence to kinematic setpoints concerning the pilgrim step movement of the detaching rollers. An advantageous solution has been found when the previously claimed ratio is between 4 and 5. A further advantageous influence on the reduction of the acceleration curve is when the connecting lines from the point of articulation on the connecting rod on the rocker and from the centre of the rocker to the point of articulation of the supporting lever on the rocker form an angle which is more than 18°. It is preferably proposed that the enclosed angle is between 20° and 35°. Further advantages of the invention are shown in an embodiment illustrated and described below, wherein: Fig. 1 shows a drive apparatus with the unevenly driven eccentric and a differential gear in a vertical sectional view; Fig. 2 shows the drive apparatus of fig. 1 in a side view along line ll-ll of fig. 1; Fig. 3 shows the drive apparatus of fig. 1 in a schematic plane view; Fig. 4 shows a graphical illustration of the sequence of movements of the detaching rollers. As is shown in fig. 1, a circular comb shaft 1 which is held in a machine frame 7 of a combing machine is driven by a drive shaft 25 by way of a toothed wheel 26 which is seated on the same and by a toothed wheel 3 seated on the circular comb shaft 1. Drive shaft 25 receives its drive from a motor (not shown) by way of a V-belt pulley 24. An adjusting disk 4 which is connected with toothed wheel 3 via an adjusting screw 6 is disposed on the circular comb shaft 1, with a drawbar 10 being articulated on said disk at a point of articulation E by means of a pin 5, as is also shown in fig. 2. As is further shown by figs. 2 and 3, drawbar 10 acts on an eccentric 8 by means of a pin 9 at a point of articulation D. if eccentric 8 is made to move by the circular comb shaft 1 by way of adjusting disk 4 and the drawbar 20, this movement (as is shown in figs. 1 and 2) is transmitted by the eccentric 8 onto a rocker 11 which is articulated by means of a pin 15 on a supporting lever 14 in a supporting lever hinge point J, with the supporting lever 14 being held on a nipper drive axle 22 while the rocker 11 is hinge-connected with a connecting rod 16 on the opposite point of circumference on a point of articulation G via a pin 12, which connecting rod is articulated with a point of articulation F on a control lever 17 by way of a pin 19. The control lever 17 is rigidly connected with an axle 20 of a differential gear 21. A bridge 30' of the differential gear 21 further receives (as is further shown in fig. 1) a rotational movement acting in one and the same direction with an even speed of rotation from a toothed wheel 27 disposed on the circular comb shaft 1 via an intermediate wheel 28 disposed on a pin 29 situated in the machine frame 7 and via bridge wheel 30. Said rotational movement is communicated to a planet wheel 32 which is connected in the differential gear 21 and with its bridge 30' and which rolls off on a sun wheel 31 which is fixedly disposed on a differential gear axle 20 and is connected with a planet wheel 32' and transmitted via a sun wheel 33 which is rotatably held on the differential gear axle 20 and is connected with a toothed wheel 34 and further onto detaching rollers 23 via toothed wheels 35, 36 and 37 held outside of the differential gear 21. The movements of eccentric 8 make rocker 11 perform eccentric movements which are transmitted onto control lever 17 by the connecting rods 16 which are attached to the point of articulation G on rocker 11 via point of articulation F and thus onto the differential gear axle 20 of the differential gear 21 and is transmitted in the same onto the detaching rollers superimposed in the same with the rotational movement produced by the circular comb shaft 1 in one and the same direction and with even speed of rotation. The connecting straight line VG (fig.3) between the supporting lever hinge J and the point of articulation G of rocker 11 forms an acute angle a with the straight line between the supporting lever hinge J and the centre C of rocker 11. Since the rocker 11 is swivellable on the supporting lever hinge J about a point of articulation K of supporting lever 14 on the nipper drive axle 22, the centre point C of rocker 11 is moved during the movement of the eccentric 8 on an orbit Kz with a centre point B, as a result of which the point of articulation G moves along an ellipse-like path Eg. The movements of the point of articulation G along the ellipse-like path Eg produce circular movements according to a circular curve Ks for point of articulation F as a result of connecting rod 16, with the point of articulation F and thus the control lever 17 oscillating about a point of rotation H. The ellipse-like path Eg can therefore be designated as a connecting curve. As is further shown in fig. 3, the centres A of the circular comb shaft 1 and B of the eccentric 8 do not coincide, which is why during the rotation of the drawbar 10 the point of articulation E of the same will rotate on an orbit KE about the centre point A of the centre of the circular comb shaft 1 and the point of articulation D of the same will rotate on an orbit KD about the centre point B of the centre of the eccentric 8. The eccentric 8 is thus unevenly driven. Due to the supporting lever 14 the rotational movements produce a movement on the orbit Kz with the centre point B (the rotational axis of eccentric 8) for the centre C of rocker 11 and for the point of articulation G movements on the ellipse-like path Eg, with the point of articulation G performing a circulation from G' via G" and G'" back to G' again. For example, a position of the point of articulation D at D' or of the point of articulation E at E' correspond to the positions of the centre of the rocker C at C, of the supporting lever hinge point J at J' and of the point of articulation G at G' (shown with the broken line). The zone G' to G" which the point of articulation G passes through on the ellipse-like path Eg therefore causes a rapid return movement of the detaching rollers 23 (return delivery) by the movements of the point of articulation F and the control lever 17, the zone G" to G'" a forward movement of the detaching rollers 23 (detachment of the fibre material) and the zone G'" to G' a standstill of the detaching rollers 23. A movement of the point of articulation F on the orbit from F to F" corresponds to a movement of the point of articulation G on the ellipse-like path Eg from G' to G", thus making control lever 17 perform a rapid movement, causing the detaching rollers to perform a reverse movement which continues until reaching G" of the point of articulation G. As a result of the further movement of the point of articulation G from G" in the direction towards G'", the point of articulation F moves from the position F" on the orbit Kg back in the direction F. The control lever 17 turns back in the reverse direction and thus provides the detaching rollers with a forward movement which continues until the point of articulation G has reached the position G'" on the elliptical path Eg and thus the point of articulation F has reached the position F on the orbit Kg. During a movement of the point of articulation G on the ellipse-like path Eg between G'" and G' the point of articulation F remains in its position near F, thus practically corresponding to a standstill of the control lever 17 and thus the differential gear axle 20 and, in addition, the detaching rollers 23 with respect to the additional overlapped rotational movement given to the differential gear 21 and thus the detaching rollers. In order to ensure that the point of articulation F remains in the position F it is necessary that the point of articulation G moves in section G'" G' of the ellipse-like path Eg on an approximate orbit about the point of articulation F. As is shown in fig. 3, the path G'" G' corresponds to the ellipse-like path Eg of an orbit with its centre point at the point of articulation F. During a movement of the point of articulation E on orbit KE about the centre point A of the circular comb shaft 1 of more than 180° the point of articulation D of the drawbar 10 will rotate less than 180° on the orbit KD due to the unevenly driven eccentric 8 and the point of articulation G will move on one in the section from G'" to G' of the ellipse-like path Eg which covers less than 180°, as a result of which the control lever 17 will come to a standstill by more than 180° of a nip of the comb. In the illustrated drive apparatus the dwell time of the point of articulation F is extended over 180° of a nip of the comb by the uneven drive of the eccentric 8, which is not achieved by a simple crank mechanism in which the centre of the circular comb shaft and the centre of eccentric 8 coincide. The path of movement of the point of articulation G which is produced by the revolving eccentric 8 over the centre C of rocker 11 oscillating on orbit Kz thus causes the reciprocating movement of the point of articulation F on orbit Ks between the positions F and F" which are transmitted onto differential gear 21 and, subsequently, onto the detaching rollers by way of the control lever 17 and the differential gear axle 20, as a result of which they perform a rapid reverse movement and thereafter a forward movement and come to a standstill by way of the dwell time of the point of articulation F in the position F which corresponds to the path of the point of articulation G on the elliptical path EB between G'" and G'. The adjustment of the respective time at which reverse and forward movement and standstill are initiated for the detaching rollers 23 is performed by means of adjusting screw 6 on the adjusting disk 4, thus enabling the points G', G" and G'" to be displaced and fixed to the desired extent. An influence on the pilgrim step movement can also be achieved in such a way that the point of articulation E on adjusting disk 4 is angularly adjusted not only with respect to the driving toothed wheel 3 for the circular comb shaft 1, but also by changing the length of the drawbar 10 by exchanging the same or by using a length-adjustable drawbar 10. The point of attack E of the drawbar 10 on the adjusting disk 4 can be provided in a radially adjustable manner, so that the crank throw for the movements of the eccentric is changed. In this manner it is possible to substantially control the ratios. References to the aforementioned settings are also disclosed in the corresponding USPS 3,584,346 from figs. 4 and 5 in addition to their descriptions. Fig. 4 shows the acceleration curve (m/s2) over the duration of a nip of the comb. A nip of the comb is broken down into 40 indexes, i.e. a circular comb revolving at a constant speed performs a complete rotation within said 40 indexes. The curve shown with the continuous line shows the progress of the acceleration of the detaching rollers during a nip of the comb with the drive apparatus as proposed in accordance with the invention at 400 nips per minute. The dot-dash line, however, shows the acceleration curve of the detaching rollers with 350 nips per minute of the current solution. The progress of the curves shows that up to index 17 the acceleration has risen to the highest point. The detaching and piecing process begins approx. at index 16, with the direction of rotation of the detaching rollers being reversed in order to draw off a fibre package from the end of the fibre tuft supplied to the nipper and to piece it together with the end of the formed fleece layer. The detaching process is approximately completed at index 24. As is shown in the illustration, the acceleration between the curve with the solution as claimed in accordance with the invention (continuous line) and the curve of the current solution (dot-dash line) shows a difference x in the upper range and a difference y in the lower range although the solution is already operated with 400 nips per minute. This means that as a result of the gear unit as designed in accordance with the invention with the specially designed gear ratios it is possible to reduce the required acceleration of the detaching rollers and thus to simultaneously minimise the acceleration forces. This allows increasing the nip counts without allowing the mechanical forces on the drive elements and their bearings to rise over the ones currently encountered. Claims 1. A drive apparatus for detaching rollers (23) in a combing machine with a differential gear (21) whose one primary shaft is connected with a drive imparting said primary shaft with an even rotational movement and whose other primary shaft is connected with a control apparatus imparting an additional rotational movement, with an eccentric (8) held on the frame, which eccentric is connected via a drawbar (10) with a crank (A, E) which imparts the eccentric with an uneven rotational movement of constant drive speed and is held in a manner as to be offset from the point of rotation (B) of the eccentric, with the eccentric (8) bearing a rocker (11) which is supported at a circumferential point (J) in an articulated manner on a supporting lever (14) which is rotatably held on the frame, which rocker, for the transmission of a movement imparted to it by the eccentric, is connected by way of a connecting rod (16) with a control lever (17) of the said other primary shaft (20) for the additional rotational movement, characterized in that the ratio of the distance between the point of articulation (D) of the drawbar (10) on the eccentric (8) and its point of rotation (B) to the distance between the centre (C) of the rocker (11) and the point of rotation (B) of the eccentric (8) is chosen larger than 3.5. 2. A drive apparatus as claimed in claim 1, characterized in that the ratio of the distance between the point of articulation (D) of the drawbar (10) on the eccentric (8) and its point of rotation (B) to the distance between the centre (C) of the rocker (11) and the point of rotation (B) of the eccentric (8) is preferably chosen between 4 and 5. 3. A drive apparatus as claimed in one of the claims 1 to 2, characterized in that the connecting lines from the point of articulation (G) of the connecting rod (16) on rocker (11) and from the centre (C) of the rocker (11) to the point of articulation (J) of the supporting lever (14) on rocker (11) form an angle which is greater than 18°. 4. A drive apparatus as claimed in claim 3, characterized in that the enclosed angle is preferably between 20° and 35°. 5. A drive apparatus for detaching rollers substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

246-mas-2000-abstract.pdf

246-mas-2000-claims filed.pdf

246-mas-2000-claims grand.pdf

246-mas-2000-correspondence others.pdf

246-mas-2000-correspondence po.pdf

246-mas-2000-description complete filed.pdf

246-mas-2000-description complete grand.pdf

246-mas-2000-drawings.pdf

246-mas-2000-form 1.pdf

246-mas-2000-form 19.pdf

246-mas-2000-form 26.pdf

246-mas-2000-form 3.pdf

246-mas-2000-form 5.pdf

246-mas-2000-other documents.pdf

246-mas-2000-verification documents.pdf