Antirotation device for tray

In a tray conveying device comprising a guide groove for guiding both sides in a carrying direction of a disk-like tray with a yarn feed package stood upright and a drive belt for supporting a bottom of the tray to carry it along the guide groove, a roller which is guided by an upper end edge of the guide groove is provided at a position away from the center of the upper surface of the tray.

FIELD OF THE INVENTION 
The present invention relates to an antirotation device for a tray in a 
tray conveying device for conveying a tray carrying with a yarn feed 
package placed thereon. 
RELATED ART STATEMENT 
In a two-for-one twister or the like, a tray conveying device is used for 
the purpose of supplying a yarn feed package to each of its units. This 
tray conveying device includes the case for carrying a single yarn feed 
package with two ply yarns wound and the case for carrying a so-called 
two-stage type yarn feed package in which a yarn feed package with single 
yarns wound is overlaid in two stages. 
FIG. 5 shows the case for carrying a two-stage yarn feed package (Japanese 
Utility Model Application No. 116055/1989) previously filed by the present 
applicant. In FIG. 5, reference numerals 1 and 2 designate single yarn 
packages which are wound about a take-up tube 3. These packages 1 and 2 
are fitted in the outer periphery of a cylindrical adapter 4 in upper and 
lower stages to constitute a two-stage type yarn feed package 5. The 
adapter 4 has a portion 4a, at which the lower stage package 2 is 
positioned, formed into a conical configuration along the inner shaper of 
a truncated conical take-up tube 3, and a portion 4b, at which the upper 
package 1 is positioned, formed into a cylindrical shape. The adapter 4 is 
formed at its lower end with a flange 6 for stopping the lower end of the 
take-up tube 3 of the package 2. A spacer 7 having a fitting portion 7a, 
in which the lower portion of the take-up tube 3 of the upper stage 
package 1 is fitted, is loosely fitted in the outer periphery of the 
adapter 4 between the upper and lower packages 1 and 2. A defining member 
(in which a resin fine wire is mounted in a flange-like manner) 8 for 
defining a yarn Y2 released from the lower stage package 2 such that the 
yarn Y2 does not contact with a lower edge A of a yarn layer of the upper 
stage package 1 is mounted on the spacer 7. 
The adapter 4 is integrally formed in the upper end with a cylindrical top 
cap 9 for inserting and guiding the yarns Y1 and Y2 released from both the 
packages, 1 and 2 into an adapter 4 through an axial hole. Both yarn ends 
are subjected to yarn end finding from the surfaces of the yarn layers of 
both of the packages 1 and 2 and are wound around the upper end of the top 
cap 9. The top cap 9 is formed with an annular inflated portion 10 to 
prevent a wound portion B of the yarn end from being loosened and 
disengaged. 
In order to carry the thus structured two-stage type yarn feed package 
(clip cone) 5, a disk-like tray 12 with a peg 11 projected to make the 
package 5 stand up and a tray conveying device 13 for carrying the tray 12 
are used in the central portion of the upper surface thereof. The tray 
conveying device 13 is principally composed of a guide groove 14 for 
guiding both sides in a carrying direction of the tray 12 and a drive belt 
15 for carrying the tray 12 along the guide groove 14 supporting a bottom 
of tray 12. In this case, a round belt is used as the drive belt 15 in 
order to allow the belt to continuously pass drive belt along the guide 
groove having a straight line portion and a curved line portion, and the 
drive belt 15 is arranged so as to support the tray from a position 
deviated from the center of the tray bottom. 
The bottom face 12a of the tray 12 is supported by the bottom frame 16a and 
the drive belt 15, and the tray 12 is transferred by the drive belt 15. If 
the drive belt is extended below the center portion of the tray, the 
rotation of the tray may be prevented but the edge portion of the tray is 
easily moved up or down. So, the drive belt 15 is arranged at a position 
deviated from the center of the bottom face 12a of the tray 12. 
However, in the aforesaid tray conveyor 13, an axial rotational moment 
occurs in the tray 12 because of the presence of the drive belt 15 at a 
position deviated from the center. A rotation as indicated by the arrow 
shown in FIG. 5, therefore, occurs during carrying. Particularly, in the 
case of the two-stage type yarn feed package 5, a deviation of rotation 
occurs between the tray 12 and the adapter 4 or between the upper and 
lower packages 1 and 2 due to a difference in vibration and friction 
coefficient, resulting in problems such as the yarn end wound about the 
top cap 9 being broken or disengaged, or the yarn end Y2 of the 
lower-stage yarn feed package 2 becoming wound between the upper and lower 
packages 1 and 2 and breaking so that it cannot be released. 
OBJECT AND SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide an 
antirotation device for a tray which can prevent rotation of the tray 
during carrying and can overcome inconveniences such as yarn breakages 
occurring during the carriage of the two-stage yarn feed package. 
For achieving the aforesaid object, the present invention provides, in a 
tray conveying device having a guide groove for guiding both sides of a 
disk-like tray with a yarn feed package stood upright thereon in a 
carrying direction and a drive belt for supporting a bottom of the tray to 
carry it along the guide groove, an arrangement wherein a roller for 
guiding along an upper end edge of said guide groove is provided at a 
position away from the center of the upper surface of the tray. 
The tray carried by the drive belt along the guide groove is subjected to a 
rotational moment by the drive belt. However, the roller provided on the 
tray comes into contact with the upper end edge of the guide groove to 
thereby eliminate the rotational moment whereby the rotation of the tray 
is impeded. Accordingly, inconveniences such as yarn breakages produced 
during the carrying of the two-stage type yarn feed package is overcome.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
One embodiment of the present invention will be described hereinafter with 
reference to the accompanying drawings. 
In FIGS. 1 and 2, reference numeral 12 designates a disk-like tray, in the 
central portion of the upper surface of which is projected a peg 11 for 
supporting a yarn feed package in an upright state. In this embodiment, a 
two-stage type yarn feed package 5 is used as a yarn feed package. The 
same parts as those shown in FIG. 5 are indicated by the same reference 
numerals, description of which are omitted. 
A tray conveying device 13 for carrying the tray 12 is provided with a 
frame 16 formed with a pair of opposed guide grooves 14 for guiding both 
sides in a carrying direction of the tray 12. The tray 12 is prevented 
from being tipped over by an upper flange 17 of the frame 16. 
A round drive belt 15 for carrying the tray 12 while supporting the bottom 
thereof is extended along a guide groove 14 in the state where the belt 15 
is closer to one of the guide grooves 14 than the other (on the right hand 
in the FIG. 1). 
As a device for preventing rotation of the tray 12 being carried, a roller 
18 (called also a first roller) which moves along an upper end edge of the 
guide groove 14, i.e., an end edge 17a of the upper flange 17, is 
rotatably mounted by a pin 19 at a position deviated from the center C on 
the upper surface of the tray 12. A projection may be provided instead of 
the roller 18. However, a roller is necessary in order to reduce friction 
with the end edge 17a of the upper flange 17 to secure smooth movement of 
the tray 12. Furthermore, in order to impede the rotation of the tray 12, 
it is necessary that roller 18 be mounted a distance n from the center C 
such that is n&gt;m, where m represents the distance from the center C of the 
tray 12 to the end edge 17a of the upper flange 17. 
One roller will suffice to impede the rotation of the tray 12. However, in 
case of one roller, when the tray 12 moves from a straight line portion 
13A to a curve portion 13B on the conveying device 13, it is subjected to 
shock depending upon the direction of the tray 12, as shown in FIG. 3. In 
order to overcome this, in this embodiment, a second roller 20 with the 
end edge 17a of the upper flange 17 as a guide is provided ahead in a 
carrying direction of the first roller 18. A guide member 21 is provided 
on the curve portion 13B parallel with the end edge 17a so as to define a 
passage for both rollers, 18 and 20 between the end edge 17a of the upper 
flange 17 and guide member 21, as shown in FIGS. 3 and 4. The addition of 
the second roller 20 causes the direction of the tray 12 to change to the 
advancing direction before the first roller 18 moves from the straight 
line portion 13A to the curve portion 13B, thereby relieving the shock 
applied to the first roller 18. 
The operation of the embodiment will be described hereinafter. 
The tray 12, both sides of which are engaged with the guide groove 14, is 
carried along the guide groove 14 as the drive belt 15 travels since the 
bottom thereof is in contact with the drive belt 15 and moves with the 
two-stage type yarn feed package 5 placed thereon. The axial rotational 
moment occurs in the tray 12 due to the presence of the drive belt 15 
during carrying. However, since the first roller 18 provided on the tray 
12 is in contact with the upper end edge 17a of the guide groove 14, the 
rotational moment is eliminated to and impedes the rotation of the tray 
12. Accordingly, inconveniences such as yarn breakages produced during 
carrying of the two-stage type yarn feed package 5 is overcome. 
Furthermore, in the curve portion 13B of the tray conveying device 13, the 
direction of the tray 12 is changed to the advancing direction before the 
first roller 18 moves from the straight line portion 13A to the curve 
portion 13B by the second roller 20 and the guide member 21. Therefore, 
the shock applied to the first roller 18 is relieved so that the tray 12 
can be smoothly moved along the curve portion. 
While in this embodiment, two rollers 18 and 20 are mounted on the tray 12, 
it is to be noted that a third roller 22 with the end edge 17b of the 
other upper flange 17 as a guide may be provided at a position of point 
symmetrical with the first roller 18 with respect to the center C of the 
tray 12 as indicated by the phantom line in FIG. 2. According to this, 
both the first and third rollers 18 and 22 impede the rotation of the tray 
12, and the tray 12 is urged toward the central portion widthwise of the 
tray conveyor 13 so that the end of the tray 12 does not contact with the 
side wall of the guide groove 14 to secure smooth movement of the tray 12. 
Furthermore, while in the embodiment the two-stage type yarn feed package 
has been carried, it is to be noted that a conventional package can be 
course be used. 
As described above, in short, according to the present invention, it is 
possible to impede the rotation of the tray being carried whereby 
inconveniences such as yarn breakages produced during carrying of the 
two-stage type yarn feed package can be overcome.