Retaining element on a carousel conveyor with several outlets for selective retention of conveyed containers

The retaining element is extended from a carousel disk in the plane of the disk and holds a bottle to be retained by the carousel essentially only at one point (T). The retaining element can be provided with an easily exchangeable finger part thus permitting quick and easy adaptation to different bottle sizes. As the retaining element swings out against the bottle without touching it during the swinging action, there is no risk of damage to the bottle.

BACKGROUND OF THE INVENTION 
The invention relates to a retaining element on a carousel conveyor with 
several outlets, for selectively retaining conveyed containers. It also 
relates to a carousel conveyor with a plurality of such retaining 
elements, as well as a bottle inspection apparatus with such a carousel 
conveyor. 
DE-OS 3838007 discloses a sorting star-wheel for container handling 
machines. The individual containers are held in the pockets of the sorting 
star-wheel or carousel by pivoting locks which execute a pivoting movement 
in a plane parallel with the axis of the carousel. With this known method 
of holding the containers in the carousel, when a change of bottle size 
occurs, say from 1.5 liter to 0.5 liter, the entire carousel, with many 
parts, has to be exchanged. Also there is a possibility of the container 
surfaces becoming scratched or otherwise damaged by the pivoting locks. 
SUMMARY OF THE INVENTION 
It is therefore the fundamental object of the invention to provide a 
facility for retaining the containers on a carousel with which these 
drawbacks do not occur. 
This is accomplished with a retaining element of the type stated at the 
outset in that the retaining element executes a movement essentially in a 
plane perpendicular to the axis of the carousel in order to retain or 
release the container. 
Because the retaining element executes a movement essentially in the plane 
of a carousel disk, ie. in a plane perpendicular to the axis of the 
carousel, it is possible to arrange that only the foremost part of the 
retaining element needs to be replaced upon a change of container size. It 
also follows that it is possible to keep the retaining element completely 
clear of its container while moving to the retention point and ensure it 
does not come into contact with the container until it reaches the 
retention point, which can reliably prevent damage to the container. Also, 
the container is preferably retained in such a way that it is contacted by 
the retaining element essentially only at one point when being retained.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As an example, an inspection machine for bottles, e.g. for returnable PET 
bottles, is illustrated in FIG. 1. The bottles pass via a feed conveyor 1 
onto a feed carousel 2, main carousel 3, and discharge carousel 4. During 
the feed stage, and on the main carousel, the bottles undergo various 
known inspection procedures. For example, the bottles are checked as to 
height, and are tested for the presence of a cap, presence of residual 
water, presence of foreign bodies, etc. By means of the discharge carousel 
4, the bottles are then assigned, in an upright position, to three 
different outlets 5,6,7. The outlets 5 and 6 may, for example, be provided 
for bottles which have not passed the inspections, and the outlet 7 for 
fault-free bottles which are forwarded for refilling. To retain the 
bottles in the discharge carousel 4 until they reach their assigned outlet 
point in the carousel, the retaining elements which will now be described 
are provided on the carousel 4. 
FIG. 2 shows a further arrangement which can be provided for bottle testing 
and/or sorting. This also has a main carousel 3' feeding a discharge 
carousel 4'. Running out from the discharge carousel 4' are outlets 5'6' 
and, via a worm, outlet 7'. The distributing carousel 4' also has to be 
provided with corresponding retaining elements to keep each bottle in the 
carousel until it reaches its assigned outlet, and to release it at its 
assigned outlet. 
FIG. 3 shows a vertical section through the discharge carousel 4, with the 
left half of the figure depicting the carousel set for large bottles 10, 
e.g. 1.5 liter bottles, and the right half depicting it set for small 
bottles 11, e.g., 0.5 liter bottles. Accordingly the carousel can be 
fitted with pairs of retaining elements 12,13 for large bottles; or with 
single retaining elements 15 for small bottles. Above and below the 
retaining elements are the holders (star-wheels) 17 and 18, and 17' and 
18', respectively, forming the pockets of the carousel, which rotate about 
the central axis 19 of the carousel. The holders 17 to 18' are 
exchangeable, and also adjustable in height, for adaptation to different 
bottle sizes. In place of the exchangeable upper star-wheel 17,17' 
specific to a bottle size, it is also possible to provide a star-wheel 17" 
(only partly shown in the drawing), which is adjustable in height, to 
engage the bottle neck; this star-wheel does not need to be exchanged for 
different sizes of bottle. 
Control elements 20 and 21 which control the retaining elements as 
explained in detail below are provided underneath the retaining elements 
13 and 15, respectively, and are fixed to the machine, ie. they do not 
rotate with the carousel. This control is exerted by the 
electromagnetically or pneumatically upwardly extensible control pins 22 
and 23 of the control elements 20 and 21, respectively, which can be 
brought into engagement with control vanes or levers 24 and 25, 
respectively, to control the retaining elements. The control vanes 24 and 
25 are pivotably mounted on the carousel disk 26, and a pivoting movement 
is imparted to them when they are carried past the extended pins 22 and 23 
of the control devices by the rotation of the carousel. This is 
illustrated in plan view in FIG. 4, which shows three of the total of 
twelve control vanes each in two different positions. 
The control vane 24 is shown in front of the outlet 6, and can be moved by 
the controllable pin 22 from a first position into the second position 
indicated at 24'. In the first position, indicated at 24, the control vane 
24 is positioned so that the corresponding retaining element (which will 
be described presently) retains the object contained in the pocket of the 
carousel. In the position of the control vane indicated at 24', the 
corresponding retaining element is retracted, so that it no longer retains 
the container, which runs out into the outlet 6 as the carousel rotates. 
In this way the control pin 22 determines whether or not the container 
passes into the outlet 6. The same applies to the outlet 5 in respect of 
the control vane 30, of which a first position is indicated at 30 and a 
second position at 30'. This control vane is controlled by the pin 31. 
When this pin is extended upwards, it causes the control vane to pivot 
from the position 30 to the position 30', thus causing (as will be 
described presently) the retaining element to close, thus retaining the 
container. Hence bottles entering the discharge carousel from the curved 
track 3" of the main carousel are, under the control of the pin 31, either 
retained by the retaining element so that the bottle is carried past the 
outlet 5 with the carousel; or not retained by the retaining element, so 
that the bottle passes, unassisted, into the cutlet 5. 
Those bottles which upon entering the discharge carousel have been kept in 
the carousel by the control pin 31 acting on the retaining element, and 
have not been released into the outlet 6 by the control pin 22 acting on 
the retaining element, proceed to the outlet 7, where arrangements must be 
provided for releasing the retaining element. This is performed by a fixed 
cam 28 which shifts the individual control vane or lever so that the 
retaining elements open. The control levers 29 and 29' illustrated in FIG. 
4 show the pivoting movement brought about by the cam 28 and causing the 
retaining element to open. 
A first embodiment of the retaining element operated by the control vanes 
or levers will now be described with reference to FIG. 5. In FIG. 5, the 
control lever 30, which can be turned about the pivot 32 by the closure 
pin 31, is drawn in chain-dotted outline. Mounted on this pivot 32 is a 
toothed segment 35 which is designated in one position as 35 and in its 
other position as 35'. Position 35 corresponds to closure of the retaining 
element by the pin 31. A toothed wheel 36 meshing with the toothed segment 
35 operates the actual retaining element 38, which is arc-shaped and is 
provided in its rear region with toothing 37 which meshes with the 
toothing of the wheel 36. The retaining element 38 is provided at its 
forward end with an exchangeable retaining finger 39. As can be seen from 
the figure, when the closing pin 31 projects upwards and pivots the 
control lever 30 into the position 30' when the latter passes the pin, the 
retaining element 38 is extended forwards in a circular arc from its 
retracted position between successive bottles 10,10' over the front edge 
40 of the carousel star in the plane of the carousel disk, ie. in the 
plane perpendicular to the axis of the carousel. The toothed segment is 
turned from the position 35' to the position 35, extending the retaining 
element, which then contacts the bottle 10' with its finger 39 at the 
point T and retains the bottle in the pocket of the carousel. A control 
circuit, which either extends or does not extend the pin 31 according to 
the outcome of the bottle inspection, determines through the action of the 
pin 31 whether or not the bottle 10' is retained in the carousel by the 
retaining element 38. If it is retained, the illustrated bottle 10' 
continues at least to the next outlet 6, and does not pass into the outlet 
5. 
FIG. 6 shows the same arrangement of the retaining element 38, similar 
parts being designated with the same reference symbols as in FIG. 5. Here, 
however, it can be seen that the retaining element is provided with a 
modified finger 39'. This enables smaller bottles 11 and 11' to be 
retained. It will be seen that with the retaining device which extends in 
a plane of the carousel, adaptation to small bottles sizes can be made 
merely by changing the front part 39'. This is a major advantage of the 
retaining elements according to the invention. With the smaller bottle 
size also, the bottle is retained essentially at a single point, and, in 
exactly the same way as with the retaining element in FIG. 5, there is no 
risk of scratching the bottle 10' or 11' when extension of the retaining 
element occurs. 
FIG. 7 shows a simplified embodiment of the retaining element according to 
FIGS. 5 and 6. Similar elements are again designated with the same 
reference numbers. The toothed wheel 36 is eliminated in this embodiment. 
This results in a reversal of the action of the control cam. Accordingly, 
extension of the retaining element is now effected by the control pin 31' 
which is located on the opposite side of the pivot of the control cam 30 
to the control pin 31 according to FIGS. 5 and 6. 
FIG. 8 shows a further embodiment of retaining element; in this case, the 
rear part of the retaining element connected to the finger 39 is 
constituted by a guided flexible element 40'. In FIG. 8 this is a length 
of chain 40' driven by a chain wheel 41. The chain wheel 41 is actuated in 
turn by the control vane, as has already been described with reference to 
the preceding embodiments. Instead of the chain 40', a toothed belt or a 
spring steel strip, a spring, or a Bowden cable, could also be used as the 
flexible element. This retaining element also possesses the aforementioned 
advantages that only the front part 39 needs to be replaced when there is 
a change of bottle size, and that the extension action in the plane 
perpendicular to the axis of the carousel involves no risk of damage to 
the bottle retained. 
FIG. 9 shows a further embodiment of retaining element. Here similarly, a 
control vane or cam 51 and 51' pivotably mounted on the pivot 50 is 
illustrated which is actuated by the control pins in the manner which has 
already been described. In this case a bar 53 which can be slid along a 
linear guide 52 is provided as the retaining element. The front end of the 
bar 53 is fitted with a swivel part 54 to Which the finger 39 is attached. 
The swivel part 54 is pivotable about a pivot 55. Pivoting of the swivel 
part 54 is derived from the linear motion of the bar 53 imparted by the 
control vane, by a curved cam slot 56 into which a pin 57 on the swivel 
part 54 engages. Upon extension of the bar 53, this causes the finger 39 
to pivot about the pivot 55 so that the finger, illustrated in the 
retracted condition at 39', again makes essentially point contact with the 
bottle 10' at the point T upon extension of the bar 53, and does so 
without contacting the bottle at any other point and thus possibly causing 
damage as it is extended. In order to secure the bar 53 in the guide 52 
with friction to prevent undesired displacement (ie. displacement not 
effected by the control vane), compression springs 58 can be provided to 
press against the side walls of the guide in order to prevent looseness of 
the bar 53 in the guide 52. These springs may also be arranged in the 
guide to reduce the mass of the moving parts. Similar damping elements may 
be provided to inhibit free movement in the other embodiments which have 
been described; for example, these elements may act on the control vanes 
or levers. 
FIG. 10 shows the same embodiment as FIG. 9, but has a modified finger part 
39 attached to the swivel part 54, this modified finger part enabling 
small bottles 11' to be retained. 
FIG. 11 also shows a top view of the carousel with retaining elements 
according to FIGS. 9 and 10, the left half of FIG. 11 depicting retaining 
elements provided with fingers for larger bottles 10 and the right half of 
the figure depicting the same retaining elements provided with fingers for 
smaller bottles 11. Of course, only one or other type of finger would 
actually be used as the carousel is set for bottles of one size. FIG. 11 
is merely intended to demonstrate that with the retaining elements shown 
only the finger part 39 needs to be exchanged when resetting the elements 
to other bottle sizes. 
FIG. 12 is a similar view to FIG. 11, in this case with curved retaining 
elements as described with reference to FIGS. 5 and 6. In this case these 
retaining elements are also provided with compression springs to hold them 
securely in their guides. It will also be noticed from FIG. 12 that even a 
container 60 whose shape is not round can be held in the carousel by the 
retaining elements. Thus the retaining elements according to the invention 
and carousels to which these are fitted need not be restricted to round 
bottles, cans or similar containers; square bottles, cans or other 
containers can also be securely retained by the retaining elements. The 
same is true of other shapes, e.g. triangular shapes.