Shuttle return conveyor mechanism

The conveyor belt for the shuttle return conveyor mechanism is formed with a support on the upper surface for laterally supporting a series of shuttles thereon and drivers which act as abutments for moving the shuttles from the catching mechanism to the picking mechanism of the weaving machine. The shuttles are thus conveyed directly on the conveyor belt and do not require separate guides or channels in the weaving machines.

This invention relates to a shuttle return conveyor mechanism. 
As is known, in weaving machines which are operated with weft picking 
projectiles, such as shuttles, for example wherein ten to twenty shuttles 
are projected through a shed in successive fashion from a catching side to 
a picking side of the weaving machine, the shuttles are usually returned 
from the catching side to the picking side by various mechanisms. In some 
cases, the shuttles are returned via an endlessly rotating conveyor chain 
provided with drivers. For example, it has been known to position the 
shuttles laterally of the endless chain within a groove in the weaving 
machine frame or in a return casing accommodating the complete return 
mechanism and to use the drivers to push the shuttles along the groove. In 
such cases, the drivers may, for example, consist of a plain or 
plastics-coated bent portion of a side plate of the conveyor chain. The 
drivers may also be formed of individual pieces which are snapped over the 
chain, e.g. over a pair of side plates of the chain, by spring action so 
as to be held in place in a positive manner via apertures adapted to the 
shapes of the side plates. 
However, these return conveyor mechanisms have several disadvantages. 
Specifically, the shuttles which are guided laterally of the conveyor 
chain receive impacts from the drivers due to forces occurring as a result 
of vibrations in the machine, for example due to the beating up of the 
reed. In addition, vibrations may build up via the drive of the conveyor 
chain and result in corresponding amplified impacts if the conveyor chain 
is of a relatively heavy mass. As a result, the shuttles sometimes lead 
relative to the drivers and may knock against a preceding driver or, at 
the end of the return mechanism, against other parts of the weaving 
machine. This may interfere with operation and the shuttles themselves. 
Further, the parts that they knock against may be damaged or worn so that 
both the shuttles and these other parts of the weaving machine require 
replacement. 
In one known return mechanism, such as described in Swiss Pat. No. 606,554, 
the conveyor is in the form of a return chain or belt with a support for 
the shuttles and the drivers are disposed at the top of the conveyor. 
Since the shuttles are carried on the conveyor itself in this mechanism, 
the above mentioned risks of damage due to impacts of the drivers is 
reduced. However, here again, a guide groove or guide channel is used with 
fixed side guide walls to support the shuttles. Consequently, the return 
mechanism is not only complicated but there is also a risk of the shuttles 
jamming in the guide channel particularly upon entry of the shuttles into 
the picking mechanism and upon transfer from the catching mechanism to the 
return mechanism. Further, a separate guide of this kind requires a 
considerable amount of space. This has an unfavorable effect particularly 
in the case of shuttles being transported on the the conveyor since the 
system already requires more space as compared with the lateral drive for 
the shuttles. Still further, the rubbing of the shuttles against the guide 
walls is an additional source of noise and wear. 
Accordingly, it is an object of this invention to provide a shuttle return 
conveyor mechanism having reduced susceptability to inertia forces and 
wear so that the life of the drivers and the shuttles is lengthened. 
It is another object of the invention to provide a shuttle return conveyor 
mechanism for a weaving machine which requires limited space. 
It is another object of the invention to provide a shuttle conveyor 
mechanism of simple construction. 
It is another object of the invention to reduce the wear on shuttles which 
are returned from a catching side to a picking side of a weaving machine. 
Briefly, the invention provides an endless conveyor belt for a shuttle 
conveyor mechanism which has support means on at least one longitudinal 
side for laterally supporting a series of shuttles and a plurality of 
spaced apart drivers for individually abutting each shuttle supported in 
the support means. 
The effect of this construction is that the return mechanism can directly 
accommodate the shuttles (weft picking projectiles) without requiring any 
separate guide channels or walls. The conveyor mechanism can thus be 
disposed directly beneath the picking and catching mechanisms of a weaving 
machine without requiring excessive extra space. 
In one embodiment, the support means includes a plurality of longitudinally 
spaced supports which are distributed over the length of the conveyor 
mechanism for individually supporting the shuttles. 
Where the endless belt is constructed of a plurality of interconnected 
plates which define an endless chain, each support is mounted on the 
chain. In this regard, each support has a pair of upstanding walls to 
define a U-shaped channel for receiving at least a part of a shuttle 
therein and may be pushed onto the chain, for example in a snap fit 
relation. 
In another embodiment, the endless belt may be toothed while the support 
means is integral with the belt.

Referring to FIG. 1, only those parts of a weaving machine necessary for an 
understanding of the invention are illustrated. To this end, the weaving 
machine has a picking mechanism 12 on one side of a shed (not shown) for 
picking a series of shuttles (weft picking projectiles) 10 through the 
shed to a catching mechanism 14 on the opposite side of the machine along 
a picking line 16. In addition, a shuttle return conveyor mechanism 18 is 
employed to return each shuttle 10 from the catching mechanism 14 to the 
picking mechanism 12. As indicated, a plurality of drivers 24 are mounted 
on the conveyor mechanism 18 to push and position the shuttles 10 in the 
picking mechanism 12 for centering each shuttle 10 before entry of the 
shuttle into the picking mechanism 12. An end block 20 also acts as a 
bearing for a rotatably mounted shuttle lift 22 which lifts a received 
shuttle 10 into a picking position as is known. A shuttle stop 26 is also 
positioned downstream of the block 20. During operation, each shuttle 10 
is advanced by a driver 24 into the lift 22 until abutting against the 
stop 26. 
Referring to FIG. 2, the return conveyor mechanism 18 is constructed of a 
plurality of interconnected plates 42 which are connected together in any 
suitable fashion, such as via pins, to define an endless chain. As 
indicated in FIG. 1, the chain is looped about a pair of rollers and is 
driven in the direction indicated by arrows. In addition, the conveyor 
mechanism 18 has a plurality of U-shaped links 28 mounted on one side of 
the chain to define a series of longitudinally spaced support means for 
individually receiving and laterally supporting a shuttle 10 therein. The 
drivers 24 are mounted on the chain in alternating manner with the support 
means defined by the links 28 in order to abut a respective shuttle 10 in 
a respective support means. 
As shown in FIGS. 2, 4, and 5, each link 28 has a support base 30 on which 
a part of a shuttle 10 is received and a pair of upstanding walls 32, 34 
to define a U-shaped channel for the shuttle 10. Each sidewall 32, 34 
carries an integral U-shaped clamping member 36, 38 on the outside which 
is held in friction fit relation in a corresponding recess 40 in the 
outermost side plates 42 of the chain. To this end, each link 28 and the 
integral clamping members 36, 38 are made from plastic. 
Alternatively, each link 28 may be fixed to the side plates 42 by gluing or 
riveting. Further, the links 28 may be injection-molded around the side 
plates 42. 
Referring to FIGS. 2 and 3, each driver 24 is fixed to the side plates 42 
by clamping members 36, 38 in the same way as the links 28. In addition, 
each driver 24 has a solid body 44 having a top boundry surface 46 between 
two upstanding flanges and front and rear walls 48, 50 each of which act 
as an abutment surface for a shuttle 10. 
As indicated in FIG. 2, during transport, each shuttle 10 is held in an 
upright manner in a channel formed by a plurality of successive links 28 
and bounded longitudinally by the abutment surfaces 48, 50 of two drivers 
24. 
Referring to FIGS. 6 to 8, wherein like reference characters indicate like 
parts as above, the shuttle return conveyor may alternatively be 
constructed as a one piece endless belt having a plurality of teeth 52 on 
an inner surface and a plurality of links 54 and drivers 56 integrally 
mounted on an outer surface in alternating manner. As shown, each link 54 
is defined by a pair of side walls 32, 34 while the drivers 56 are defined 
by solid bodies 44 as above. As indicated, the pairs of side walls 32, 34 
define a series of longitudinally spaced U-shaped support means for 
individually receiving and laterally supporting a shuttle 10. 
In this embodiment, the entire belt is made from plastics, or rubber, with 
steel ply or glass fiber reinforcement. In this case, the support can also 
form a cohesive side wall so that it is only necessary to provide 
trough-shaped recesses in the belt to receive the shuttles. The side walls 
32, 34 can alternatively, be apertured or be constructed in the form of a 
fence by means of vertical projections.