Needle bar carrier

In a needle bar carrier with a needle bar comprising a plurality of needles anchored in a plastic bar, the needle bar being attachable to the needle bar carrier by form locking and for the purpose of achieving a very stable connection between the needle bar and the needle bar carrier along with a simple and defined release it is provided that the plastic bar is arrested in holes of the needle bar carrier by the plastic material of the plastic bar being thermally or chemically joined by solving or melting while forming a projection extending into or beyond the hole.

FIELD OF THE INVENTION 
The invention relates to a needle bar carrier for textile machinery, in 
particular for combing machines, open-end spinning machines as well as 
intersecting machines with a needle bar comprising a plurality of needles 
anchored in a plastic bar, the needle bar being attachable to the needle 
bar carrier by form locking. 
BACKGROUND OF THE INVENTION 
The needles of the needle bars of textile machines of the generic kind are 
subject to wear during operation or they may break off. Therefore it is 
necessary to replace the needle bars after a certain time of operation. 
Consequently, such needle bars must be connected with the needle bar 
carrier in a manner easy to insert and easy to release, on the other hand 
it must be ensured during operation that the needle bars are absolutely 
safely arrested in the needle bar carrier. 
Various arresting techniques have been developed to this effect. It is 
known in particular to arrest needle bars with a metal root in the needle 
bar carrier or in a longitudinal groove of the latter by soldering. 
Furthermore, arresting by way of an adhesive has been disclosed. Other 
solutions teach to provide the side walls of the needle bar root with 
burllike projections, so that the needle bars can be inserted into 
corresponding grooves of the needle bar carrier in the way of a 
slide-lock. 
These prior art solutions are of disadvantage because they are neither easy 
to handle nor ensure sufficiently reliable arresting, nor can they be used 
for needle bars with a root formed by a plastic bar. 
SUMMARY OF THE INVENTION 
It is accordingly the object of the invention to embody needle bars with a 
plastic bar such that they can easily and reliably be arrested in and 
released from a needle bar carrier, in particular of metal. 
In accordance with the invention this object is attained in that the 
plastic bar is arrested in holes of the needle bar carrier by the plastic 
material of the plastic bar being thermally of chemically joined by 
solving or melting while forming a projection extending into or beyond the 
hole to thereby unite the plastic bar to the needle bar carrier. 
The invention is based on the idea of combining an attachment of purely 
mechanical form locking with an attachment by chemical or thermal 
deformation of the plastic bar with, as a result of the basic connection 
by form locking, a slight deformation of the plastic bar being sufficient 
to achieve an extraordinarily reliable arresting of the needle bar and 
with such a slight deformation being in turn easy to redress. 
In a first embodiment it can advantageously be provided that the plastic 
bar has lateral projections passing through corresponding holes of the 
needle bar carrier by lateral form locking, their free ends exiting on the 
outside of the holes being deformed thermally or chemically thus forming a 
retaining head overlapping the rims of the hole. 
As a result of the connection by form locking the needle bars are arrested 
in radial direction, i.e. in the direction of the centrifugal force acting 
upon the needle bar during operation, in this embodiment. The thermal or 
chemical deformation of the lateral projections additionally serves to 
ensure absolutely reliable arresting even in tangential direction against 
forces that act upon the needle bar in a direction opposite the direction 
of combing. 
Advantageously the free ends of the projections can be deformed by being 
passed over with a heating bar or a heating pistol. 
A needle bar thus arrested can be released without any problems by 
splitting of the retaining heads, for instance by drilling. 
To achieve an even better attachment by form locking it can be provided in 
an embodiment that the needle bar carrier is substantially J-shaped in 
cross-section, that a retaining groove for the needle bars is formed 
inside the J-profile, that at least sections of the bottom of the 
retaining grooves have recesses, and that at least in sections of the 
plastic bar root of the needle bar corresponding locking shoulders are 
arranged. This embodiment is particularly suitable for chain drawing 
equipment. 
In a further embodiment particularly suitable for cam-actuated intersecting 
machines it can be provided that the needle bar carrier is U-shaped in 
cross-section, that the plastic bar of the needle bar is inserted into the 
inside of the U-profile serving as a retaining groove, that the side walls 
of the plastic bar are essentially smooth and that the side walls of the 
plastic bar are chemically or thermally joined by melting or solving 
through holes of the U-profile. 
In particular, it can advantageously be provided that plastic bolts are 
melted onto the plastic bars of the needle bars from outside through the 
holes of the needle bar carrier to arrest the needle bar. 
Alternately it can be provided that a solvent is applied through the holes 
solving the plastic material of the plastic bar for joining. It is the 
effect of such a solvent that the plastic bar is initially solved and 
swells up so that the rim of the holes is gripped by the swollen-up 
plastic material. 
In this embodiment, too, the release of the needle bar can be realized by 
mechanical splitting, for instance by drilling.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 to 5 show an embodiment as it is suitable for instance for chain 
drawing equipment. 
FIGS. 1 and 2 show a needle bar 1 comprising a plastic bar 2 and a 
plurality of needles 3 which are inserted into a groove 4 of U-shaped 
cross-section of the plastic bar 2. The anchoring of the needles 3 can be 
made mechanically or in that they are surrounded by the plastic bar 2 by 
extrusion. 
A plurality of pin-shaped projections 6 is integrally formed on one side 
wall 5 of the plastic bar 2. A web-like locking shoulder 7' extending 
longitudinally is integrally formed at the root 7 of the needle bar 1 on 
the side facing away from the projections 6. 
FIGS. 3 to 5 show a needle bar carrier 8 of J-shaped cross-section in the 
embodiment. A retaining groove 9 is formed on the inside of the J, with a 
recess 10 extending at the foot of the retaining groove 9 and 
corresponding in cross-section approximately to the locking shoulder 7'. A 
plurality of holes 12 extend through the section 11 directed upwards of 
the needle bar carrier 8 and correspond in diameter and location to the 
projections 6. Consequently, the plastic bar 2 of the needle bar 1 can be 
inserted into the groove 9 in an oblique direction according to the arrow 
13 in FIG. 3, the locking shoulders 7' entering into the recess 10 and the 
projections 6 passing through the holes 12, so that--as seen in FIG. 
4--the free outer ends 14 of the projections 6 slightly protrude from the 
outside 15 of the wall section 11. The wall section 11 fully supports the 
needle bar 1 in the area of the plastic bar 2, when the needles 3 engage 
in the material to be combed in the direction of combing (arrow 16). 
In addition to the attachment by form locking as described above further 
arresting is achieved in that the free ends 14 of the projections 6 are 
melted with a heating bar or a heating pistol, so that this end 14 is 
spread like a rivet overlapping the rim of the holes 12. In spite of only 
a slight deformation of the projections 6 thus resulting, the combination 
with the attachment by form locking serves on the whole to achieve 
excellent arresting of the needle bar 1 on the needle bar carrier 8. To 
release the needle bar 1 it is only necessary to remove the head produced 
by melting at the free end 14 of the projections 6 by means of a drilling 
or grinding machine. 
The embodiment shown in FIGS. 6 to 12 can be used for instance for 
cam-driven drawing equipment. 
A needle bar 1' is illustrated in FIG. 6 of which the root part is in the 
form of a plastic bar 2', the needles 3' being mechanically arrested on 
the plastic bar 2'. 
A needle bar carrier 8' illustrated in FIGS. 8 to 10 is U-shaped in 
cross-section, a retaining groove 9' inside the U-profile serving to 
receive the plastic bar 2'. The plastic bar 2' of a needle bar 1' is 
pressed into this groove 9' by form locking as shown in FIG. 8. 
The side walls 11' of the needle bar carrier 8' have holes 12'. To arrest a 
needle bar 1' in a needle bar carrier 8' bolt-shaped plastic parts 6' are 
melted by means of a heating pistol not shown in the drawing and put 
through the holes 12' in molten state, so that the plastic material of the 
plastic bar 2' of the needle bar 1' is melted and bonds with the plastic 
parts 6'. Consequently, the plastic parts 6' will preferably be chosen to 
consist of a plastic material that corresponds to the plastic material of 
the plastic bar 2' or that is at least chemically similar so that the two 
plastic materials bond. 
In the variant shown in FIG. 11 the side wall 11' of the needle bar carrier 
8' has one or several oblong holes 12" instead of a plurality of circular 
holes 12'. In this embodiment arresting can take place in such a way that 
the plastic bar 2' is directly melted through the oblong hole 12" by means 
of a sort of a soldering iron or pistol so that it partially engages with 
the hole 12", that it is chemically joined by solving by means of a 
solvent, or--as outlined in connection with FIGS. 8 to 10--that molten 
plastic parts are used as a sort of locking bolts. 
FIG. 12 illustrates how the arresting of a needle bar 1' in a needle bar 
carrier 8' can take simply take place in a chemical way, by a solvent 18 
in the form of drops 19 being applied by means of a dosing device 17 into 
the lateral holes 12' and solving the plastic material of the plastic bar 
2' so that it joins. If for instance polystyrene is used as a plastic 
material for the plastic bar 2', a benzol-based or toluene-based solvent 
is suitable. Tests have shown that excellent arresting forces are achieved 
with such a combination of material. Nevertheless, a connection thus 
produced can be released simply by drilling, milling or grinding.