Process and apparatus for replacement of an empty with a full roving bobbin in a spinning machine, particularly a ring spinning machine

The process for replacing an empty roving bobbin with a full roving bobbin in a spinning machine, particularly in a ring spinning machine, in a dispensing position by an automatic roving bobbin changing device comprises taking the full roving bobbin from a storage location and putting the full roving bobbin in place of the empty roving bobbin. The full roving bobbin associated with the dispensing position is taken from one of a plurality of stand-by positions in the storage location. To provide a more automatic operation the process further comprises testing whether the full roving bobbin is present in one of the stand-by positions adjacent the dispensing position before beginning the exchange and when the absence of the full roving bobbin is indicated inducing a relative motion between the roving bobbin changing device and the stand-by positions until the roving bobbin changing device stands adjacent to one of the stand-by positions having a full roving bobbin. An apparatus for performing the process of our invention is also provided.

FIELD OF THE INVENTION 
My present invention relates to a method of and apparatus for the 
replacement of an empty roving bobbin at its roving-feeding station in a 
spinning machine with a full roving bobbin from a magazine on the machine 
and, more particularly, to a process and apparatus for roving bobbin 
replacement in a ring spinning machine. 
BACKGROUND OF THE INVENTION 
A ring spinning machine can have an automatic roving bobbin changing device 
which travels along the bobbin cross bar or the machine frame and which 
draws a full roving bobbin from a storage magazine or storage location and 
puts it in a dispensing position in the spinning machine in place of an 
empty roving bobbin. 
In the roving bobbin changing apparatus of German Open Patent Application 
No. 33 12 116 this storage magazine is provided in the automatic roving 
bobbin changing device so that the roving bobbin changing device carries 
its roving bobbin storage magazine with it. On account of its weight and 
its spatial requirements the capacity of this kind of storage location in 
its traveling roving bobbin changing device is limited. This requires 
frequent filling of the storage magazine during which the roving bobbin 
changing can not occur. 
It is also known to suspend a row of stand-by roving bobbins from the 
bobbin cross bar of a ring spinning machine as taught in German Open 
Patent Application Nos. 32 10 329 and 32 40 822. These stand-by roving 
bobbins form a magazine fixed with respect to each dispensing position and 
can be used to replace empty bobbins either by hand or by an automatic 
roving bobbin changing device as needed (German Open Patent Application 
No. 32 08 677). Because of space considerations, each stand-by position is 
associated with a plurality, usually two sometimes three or four, 
dispensing positions. 
When an automatic roving bobbin changing device moving along in the 
spinning machine acts on a dispensing position or feed position in which 
the associated stand-by position is already empty because of a change in 
this stand-by position due to another associated dispensing position, this 
automatic roving bobbin changing device can not perform its function at 
this site for lack of a full roving bobbin. 
OBJECTS OF THE INVENTION 
It is an object of the invention to provide an improved method of and 
apparatus for roving bobbin changing in a spinning machine, particularly a 
ring spinning machine, which obviates the drawbacks of the prior art. 
It is also an object of my invention to provide a process and apparatus for 
replacement of an empty with a full roving bobbin in a spinning machine, 
particularly a ring spinning machine. 
It is another object of my invention to provide a process and apparatus for 
replacing an empty roving bobbin with a full roving bobbin in a spinning 
machine which eliminates the problem associated with an empty roving 
bobbin of the reserve at the changing site. 
SUMMARY OF THE INVENTION 
These objects and others which will become more readily apparent 
hereinafter are attained in accordance with my invention in a process and 
apparatus for replacing an empty roving bobbin with a full roving bobbin 
in a dispensing position in a spinning machine, particularly a ring 
spinning machine, by an automatic roving bobbin changing device which 
takes a full roving bobbin from a storage location or reserve (magazine) 
and puts it in place of an empty roving bobbin. 
According to my invention the full roving bobbin associated with the 
dispensing position is taken from one of a plurality of stand-by positions 
in a storage location and, before beginning the bobbin exchange, first 
testing is effected of whether the full roving bobbin is present in one of 
the stand-by positions associated with the dispensing position and when 
the absence of the full roving bobbin is indicated, a relative motion 
between the roving bobbin changing device and the stand-by positions is 
effected until the roving bobbin changing device stands opposite to one of 
the stand-by positions having a full roving bobbin. Thus my invention has 
the advantage that in every case the roving bobbin changing device can 
perform its function since according to the process of my invention it is 
guaranteed that the roving bobbin changing device always has a full roving 
bobbin at its disposal for every changing process. 
There are two alternative embodiments of the process according to my 
invention. The relative motion can occur by travel of the roving bobbin 
changing device along the plurality of the stand-by positions until at one 
of the stand-by positions with a full roving bobbin and after taking the 
full roving bobbin it travels back to the dispensing position. 
Alternatively the relative motion occurs by moving stand-by positions 
which are constructed so as to be movable by the roving bobbin changing 
device which is stationary until one of the stand-by positions with a full 
roving bobbin arrives at the roving bobbin changing device. 
My invention also provides an apparatus for performing the above process 
for replacing an empty roving bobbin with a full roving bobbin in a 
spinning machine. This apparatus includes an automatic roving bobbin 
changing device movable relative to the full roving bobbins which takes 
the full roving bobbin from a storage location and puts the full roving 
bobbin in place of the empty roving bobbin. A sensing device is provided 
for detection of the full roving bobbin in the stand-by position and for 
inducing a relative motion between the roving bobbin changing device and 
the stand-by position. The sensing device can activate the traveling drive 
of the roving bobbin changing device until the full roving bobbin is 
brought to the position for delivery. Alternatively the sensing device can 
activate a drive unit for moving the plurality of stand-by positions until 
the full roving bobbin is brought to a position for delivery. 
According to my invention the sensing device can be mounted on the roving 
bobbin changing device. The sensing device advantageously has an optical 
detection unit and two light barriers which are interrupted and broken 
depending on a diameter difference between the full roving bobbin and the 
empty roving bobbin. 
In one embodiment of my invention the drive unit can drive a patterned, 
e.g. toothed wheel or sprocket which can engage a traveling chain holding 
the roving bobbins in the stand-by position and the rotation of the 
toothed wheel is controllable by the optical detection unit.

SPECIFIC DESCRIPTION 
A portion of a first embodiment of a ring spinning machine equipped with a 
set of drafting rolls 1 is shown in FIG. 1. Above the set of drafting 
rolls 1 roving bobbins 2 and 3 are shown in their dispensing positions on 
a roving bobbin cross bar 6. As is apparent the roving bobbin 3 is already 
about to run out of roving so that a replacement must occur shortly. A 
full roving bobbin 5 is found on the bobbin cross bar 6 in a stand-by 
position adjacent the nearly empty roving bobbin 3. 
Near this full roving bobbin 5, held in reserve, a sensing device 8 for 
detecting a full roving bobbin is positioned before making the 
replacement. This sensing device 8 comprises a curved piece 9 with a free 
end 11 and a free end 12 on which the detection element 13 is mounted. In 
this case the sensing device 8 is optical. The sensing device 8 is mounted 
by a stand 10 on a schematically shown bobbin changing device 4. 
As can be seen in FIG. 2 the sensing device 8 has two light barriers 14 and 
15 between both of its free ends 11 and 12. The distance x between both 
light barriers 14 and 15 is such that it is smaller than the diameter D of 
a full roving bobbin 5 but larger than the diameter d of an empty bobbin. 
Both light barriers 14 and 15 are interrupted, penetrated or broken when a 
full bobbin 5 is present directly adjacent the light barriers in the 
stand-by position 7. 
A part of a traveling drive 4A which moves the roving bobbin changing 
device 4 relative to the full roving bobbin or bobbins 5 is shown in FIG. 
1. 
Another embodiment is shown in FIG. 3 in which the light barriers 14' and 
15' are positioned at an angle to each other. Here also the distance x is 
less than the diameter D of the full roving bobbin 5 but greater than the 
diameter d of the empty roving bobbin. 
In the embodiment according to FIG. 1--in case a full roving bobbin is 
present in the stand-by position 7 associated with the dispensing position 
of the bobbin 3--the bobbin changing device 4 with the device 8 travels 
along the row of stand-by roving bobbins until it detects a full roving 
bobbin 5 mounted in a stand-by position. This detection occurs by 
penetration of the light barriers 14 and 15 in the sensing device 8. After 
the removal of the full roving bobbin 5 from the stand-by position 7 the 
bobbin changing device 4 then can travel back to the dispensing position 
under power of the traveling drive 4A and there the bobbin replacement is 
performed, that is, the empty bobbin 3 is replaced by the full bobbin 5. 
As shown in FIGS. 4 and 5 the full roving bobbins 5, 5', and 5" are mounted 
on a pulling device, for example a traveling chain 16. This traveling 
chain 16 is movable along the bobbin cross bar 6. 
In this embodiment the bobbin changing device 4 is provided additionally 
with a supporting member 20 which supports a drive shaft 21 of a drive 
unit 21a. A toothed wheel 17 with recesses 18 in its outer periphery is 
attached to the upper part of the drive shaft 21. These recesses 18 can 
cooperate with pins 19 attached to the traveling chain 16. 
Again a situation is shown in FIG. 4 in which the roving bobbin 3 found in 
the dispensing position is about to run out of roving. In this case--a 
case in which a full roving bobbin is not already in the stand-by position 
7 associated with the dispensing position of the bobbin 3--the pulling 
member containing the stand-by bobbins 5, 5', and 5", that is the 
traveling chain 16, is pushed by the bobbin changing device 4 until the 
sensing device 13 detects a full stand-by bobbin 5 at the dispensing 
position in the automatic bobbin changing device 4 and initiates the 
changing process. 
In every case it is guaranteed by the sensing device 8 according to my 
invention that the bobbin changing device 4 first finds a full roving 
bobbin 5 in the stand-by position and that the bobbin changing process can 
be performed in a desirable reliable way. 
FIG. 6 shows the program followed by the apparatus of the invention. Once 
the program is initiated the entire changer 4 is moved by the drive 4a 
under the control of the microcomputer 32 until an empty bobbin is 
detected at its sensing position, e.g. the bobbin 3. The sensing means for 
this purpose can be any art-recognized device for signalling an empty 
bobbin. Once the carriage 32 has stopped at this position, the sensor 8 
detects whether the available reserve bobbin is empty (missing) or full, 
the reserve or store of bobbins and the changer are displaced relatively 
with sensing being repeated until a full bobbin is detected. Then bobbin 
exchange is effected between position 3 and the now available full reserve 
bobbin. To this end the arms 33 and the bobbin gripper 34 can be actuated 
(FIG. 7) to grip this bobbin and effect transfer using the drive 30 (FIGS. 
7 and 8). When bobbin change is complete, the bobbin changer is shifted 
along the frame (drive 4A) until the last bobbin position is reached. 
After a time, a new bobbin change movement, e.g. of the carriage 32' in 
the opposite direction can be effected.