|Title of Invention||
|Abstract||The invention relates to a spinning frame, in particular ring spinning frame, with a multiplicity of spinning units, whereat each of said units has a drafting unit between a fibre supply and a spinning device and where on at least a plurality of those at least one suction pipe is led, between the fibre supply and the spinning device, each of said suction pipe is being connected with at least one common suction channel that is connected to a sub-pressure source. The invention is based on the fact that at least in one part of the suction pipes throttle means are being furnished with at least such a dimensioning that through each of them flows such an amount of air, in that at the suction ports of all drafting units pertaining to these section pipes, at least basically the same pressure conditions are present.|
The invention relates to a spinning frame, in particular ring spinning frame with a multiplicity of spinning units.
It is already known to arrange suction pipes at a drafting unit of a ring spinning frame in order to suck off loose fibres or fibres flying around and to convey them via a central suction duct to a fibre separating device. A suction means at each of the spinning units has a particular function in connection with condensing-type spinning, where at the exit or after the exit of the drafting unit a sieve drum or a sieve belt is provided in order to condense the fibre strand exiting from the output gap of the drafting unit pneumatically before twisting, (see e.g. DE-OS 198 05 397 Al or DE 198 46 268A1).
A problem with suction means within the area of the drafting unit of a ring spinning frame being connected to a central source of sub-pressure, in particular a suction fan, exists by the requirement to suction-off, on all individual suction pipes, at least basically the equal amount of air in order to maintain comparable pneumatic conditions in all spinning units. With condensing type spinning a possibly constant sub-pressure between 50 to 200 preferably 60 to 90 and in particular about 75 mm WS (water head) should prevail below the perforated condensing surface. It was experienced however, that the sub-pressure from spinning unit to spinning unit can vary substantially, even if the suction arrangements in each individual spinning unit are to a large extent designed equally.
The co-pending application No. 679/MAS/2001 claims a condensing device of a spinning machine. The condensing device contains a condensing element with a stationary suction element for discharging the air entering the suction element through the condensing element. The suction element consists of a housing and an insert, with the latter being displaceable with respect to the housing along a guide means and being arrestable with respect to the housing. Hence, the claimed subject matter of said application clearly differs from present invention and particularly does not claim throttle means.
The co-pending application No. 669/MAS/2001 claims a spinning machine with a condensing device for condensing a fibre structure in a drafting arrangement which comprises a condensing element with a moved surface which is penetrated by breakthroughs, with the fibre structure being guided in the zone of the breakthroughs over the surface and air being sucked in through the breakthroughs into the interior of the condensing element. The breakthroughs are provided with an oblong-hole-like arrangement transversally to the direction of guidance of the fibre structure. Hence, the claimed subject matter of said application clearly differs from present invention and particularly does not claim throttle means.
The co-pending application No. 713/MAS/2001 claims a method for guiding a sliver in a drafting unit of a spinning frame with a condensing device for condensing of the sliver by means of a suction element comprising a suction slot through which air is suctioned in through penetrations within a condensing element. The length and width of the suction slot can be changed. Hence, the claimed subject matter of said application clearly differs from present invention and particularly does not claim throttle means.
The object of the invention is to provide a spinning frame of the above specified type by which, without any problems, equal flow conditions can be obtained in all spinning units, whereby an even yam quality is ensured in all spinning units.
The task is solved according to the characteristic features of the operative part as described herem. Particularly preferred and practical embodiments are also described herein.
Thus the object of the invention is to be seen by the layout of the individual suction arrangements leading from the central suction duct to the suction port at the drafting unit and/or after the drafting unit, for example with throttle means, in particular
orifices, in a way that in the suction ports of all spinning units equal pressure ratios prevail and in particular equal amounts of air are sucked off and in all spinning units an even yam quality is thus ensured.
Influencing the amount of air flowing to the individual spinning units could be obtained in principle also through regulating valves being inserted into the suction pipes, but the provision of individual orifices represents, from the cost point of view, a particularly favourable solution.
According to the embodiment it is possible to achieve after completion of the installation of a spinning frame, that first the amount of air sucked off from the individual spinning units is measured and afterwards a suitably dimensioned orifice is attached in each suction pipe. Due to the replaceability it is possible to replace an orifice which proved unsuitable by a more suitable orifice at any time later. Also for the case of the contamination of the orifices a replaceability is favourable.
Each individual suction pipe is to be designed in accordance with the invention.
The particularly preferred application of the invention with condensing type spinning, where the exact adjustability of the amount of air in each individual suction pipe has special meaning because the amplitude of the sub-pressure within the condensing zone has a particularly large influence on the yam quality. In principle the object of the invention can be applied also, that is in other suction means within the area of the drafting unit as well as within the area before and behind it.
Since a pressure loss arises along the central suction ducts, the openings of the throttle means should usually be designed. In this way equal pressure ratios, especially equal amounts of air in the individual suction ports can be ensured.
According to a preferential further embodiment, the throttle means are to be adjustable with regard to their opening size.
The invention is described in the following by way of examples of the accompanying drawing, wherein shows
Figure 1 a schematic view of a spinning unit of a ring spinning device according to the invention, whereat for a clearer presentation the drafting unit is shown 90^ revolved around a vertical axis.
Figure 2 a schematic side view of a ring spinning frame within the area of the drafting unit and the following condensing zone, whereat the drafting unit and the pneumatic condensing device provided at its exit, again are being revolved around the vertical axle by 90° for a clearer presentation,
Figure 3 a strictly schematic illustration of the size of the openings of the orifices in dependence on the distance from the central source of sub-pressure and
Figure 4 a cross section through an adjustable orifice within a suction pipe.
According to figure 1 a roving is supplied from a roving bobbin 24 to the pair of input rollers 12 of a drafting unit 11. Between the pair of input rollers 12 and a following pair of central rollers 13, which co-operate with tapes 13, a pre-drafting takes place in the conventional manner.
After the pair of tapes 13' a pair of output rollers follows which consist of a sieve drum 15 and an output pressure roller 14. Within the sieve drum 15 there is a suction box 16 which is attached, via a suction pipe 20, to a central suction duct 18 and towards the sieve drum 15 exits into an air passage slot which runs peripheral or slanted in relation to the circumference.
At an angular distance from the output pressure roller 14 a twisting restriction roller 17 is pressed against the sieve drum 15 in the running direction of the tape. The roving 26 is drafted within the drafting unit 11 in the usual manner, then pneumatically condensed between the rollers 14, 17 and finally exits as a twisted thread 27 from the twisting restriction gap formed by the sieve drum 15 and the twisting restriction roller 17, from where it is led to the spinning device 25 by means of which the necessary spinning twist is generated.
Between the pair of tapes and the output pressure roller 14 a fiirther suction pipe 21 is positioned which is connected, for air flow communication, with a fiirther central suction duct 19. Figure 1 is to be understood merely as a schematic illustration; normally the suction pipe 21 is placed below the condensing suction port 30.
Both, in the suction pipe 20 and in the suction pipe 21, individual throttle means in the form of orifices 22 and/or 23 are arranged by which the amount of air sucked off by the suction box 26 and/or the suction pipe 21 can be adjusted to a desired value.
From figure 2 can be seen that in each case the individual suction pipes 20, 21 at all spinning units are connected to a common central suction duct 18 and/or 19 at whose ends suction fans 26 and/or 27 are provided in order to generate sub-pressure conditions within the suction ducts 18, 19. It is also possible that the two suction pipes 20, 21 are connected to one and the same central suction duct 18 or 19 respectively. According figure 1 this can take place e.g. by means of the feeder lines 40, indicated in a dashed line, said lines connecting the suction pipes 21 with the central suction duct 18.
The different orifices 20 and/or 23 in the suction pipes 20, 21 are in each case designed individually that in each case at least basically equal amounts of air flow through the individual suction pipes 20, 21 to the suction ducts 18 and/or 19. In this way 21, to a large extent, equal flow conditions prevail at the suction boxes 16 and/or
the ports of the suction pipes so that differing influences are being avoided on the yam being produced on the individual spinning units.
Figure 3 indicates the way of increase of the size of the openings 32 of the orifices 22 in relation to the distance from the suction fan 26. Since along the central suction duct 18 with increasing distance from the suction fan 26 a drop of pressure takes place, the openings 32 of the orifices 22 are larger at a larger distance from the suction fan 26 than the openings 32 of the orifices being positioned closer to the suction fan 26.
Figure 4 shows schematically a preferred embodiment of an orifice 22 and/or 23 with an adjustment mechanism for changing the effective size of the opening 32. Accordingly, besides the orifice opening 32, a cover 34 is arranged swivably around an axle 33 being positioned perpendicularly in relation to the orifice 22 and/or 23 which cover 34 in the form of a projection 35, on the side opposite the axle 33, engages in a circumferential groove 36 of an adjusting nut 37 said nut being carried on a threaded spindle 38, that can be rotated, but which is axially non-shif^ably fastened on the orifice 22 and/or 23 and/or their mounting plate and comprises an operating knob 39 at its end.
By turning the operating knob 39 in one or another direction the adjusting nut 37 can be shifted in one or another direction of the double arrow, whereat the lower end of the cover 34 in figure 4 is carried forward or backward. If the operating knob 39 is rotated in such a way that the cover 34 is swivelled in clockwise direction then it enters into the cross section of the opening 32 and thereby makes the effective air passage of this cross section smaller accordingly.
With an orifice adjustment arrangement according figure 4 the correct orifice opening can be adjusted simply in such a way that, for example with an anemometer, the amount of air sucked-in into each spinning unit is measured and is then adjusted through a fine adjustment by means of the operating knob 39 to a pre-determined value.
Generally, however, one should operate for cost reasons with orifices which have predetermined opening sizes. These orifices 22, 23 should, however, be insertable, preferably later for example via slots into the suction pipes 20, 21. The selection of the correct orifice size can for instance take place in that at first - without orifices - the amounts of air being sucked off through the suction pipes 20, 21, during operation with the suction fans 26, 27 are measured at each spinning unit. Thereafter the orifices 22, 23 for each spinning unit are selected in such a way that after their insertion into the suction pipes 20, 21 at least basically equal amounts of air flow in all suction pipes 20,21.
The orifices 22, 23 can also be replaced at any time, which is important e.g. if an orifice is dirty or if it is later realised that the selected orifice is not exactly of the correct size.
The preferred range of application of the throttle means according to the invention is in connection with condensing type spinning where exactly equal air flow conditions are particularly important at the condensing zone.
List of reference numerals
11 drafting unit
12 pair of input rollers
13 pair of central rollers
14 output pressure roller
15 sieve drum
16 suction box
17 twist restriction roller
18 central suction duct
19 central suction duct
20 suction pipe
21 suction pipe
24 roving bobbin
25 spinning unit
26 suction fan
27 suction fan
30 suction port
31 suction port
36 circumferential groove
37 adjusting nut
38 threaded spindle
39 operating knob
40 connecting line
1. Spinning frame with a multiplicity of spinning units, wherein each of said units
has a drafting unit (11) between a fibre supply (24) and a spinning device (25) and
where on at least a plurality of those at least one suction pipe (20, 21) is led between
the fibre supply (24) and the spinning device (25), each of said suction pipe is
connected with at least one common suction channel (18, 24) that is connected to a
sub-pressure source (26, 27), characterized in that at least in one part of the suction
pipes (20, 21) throttle means (22, 23) are being furnished with a dimensioning, that in
combination with the design of said suction pipes (20, 21) at the suction ports (30, 31)
of all drafting units pertaining to these suction pipes (20, 21), the same pressure
conditions prevail, and that through each of them the same amoimt of air flows.
2. Spinning frame as claimed in claim 1, wherein each throttle means is
constructed as an individual orifice (22, 23) which is inserted into the pertaining
suction pipe (20, 21).
3. Spinning frame as claimed in claim 2, wherein the orifices (22, 23) is replaced into each suction pipe (20, 21).
4. Spinning frame as claimed in claim 1 or 2, comprising a condensing device (15) wherein the suction pipes (16, 21) are arranged at the exit or after the exit of the drafting unit (11), and each of the suction pipes (20) leads to the condensing device (15),
5. Spinning frame as claimed in claim 1 or 2, wherein the size of the openings (32) of the throttle means (22, 23) increases with the increasing distance of the throttle means (22, 23) to the pertaining source of sub-pressure (26, 27).
6. Spinning frame as claimed in claim 1 or 2, wherein the effective size of the
opening (32) of at least one throttle means (22, 23) or of all throttle means (22, 23) is
changeable by adjustment means (33, 34, 35, 36, 37, 38, 39).
7. Throttle means for suction means leading to a central suction duct in a spinning
frame with a drafting unit (11), characterized in that the throttle means (22, 23) are
individually adjusted to an equal air through-put.
|Indian Patent Application Number||691/MAS/2001|
|PG Journal Number||47/2008|
|Date of Filing||21-Aug-2001|
|Name of Patentee||MASCHINENFABRIK RIETER AG|
|Applicant Address||KLOSTERSTRASSE 20, CH-8406 WINTERTHUR,|
|PCT International Classification Number||D01H1/02|
|PCT International Application Number||N/A|
|PCT International Filing date|