Pipeless filling unit for counterpressure bottling machines

The pipeless filling unit for counterpressure bottling machines includes a siphon closure consisting of a bell-shaped stopper projecting with its rim portion into an annular groove. The bell-shaped stopper is fixedly held in position in the liquid discharging channel and has a central boring for guiding an axially displaceable valve tube; the bell-shaped rim portion of the stopper is provided around the whole circumference with a plurality of vertically and radially directed slits for intercepting and rinsing away particles from the discharged liquid.

BACKGROUND OF THE INVENTION 
This invention relates generally to counterpressure bottling machines and 
more specifically it relates to a filling unit for use in such machines, 
the unit being of the type having no filling pipe and having a siphon 
closure arranged at the level of the valve seat in the liquid discharging 
channel, the siphon closure comprising a ring-shaped groove for sealing 
liquid and a bell-shaped stopper projecting with its rim portion into the 
groove. 
Filling units of this type are used chiefly for charging CO.sub.2 
--containing liquids that are discharged from a pressure tank of the 
bottling machine through the filling unit into a bottle connected to the 
latter. Prior to the initiation of the actual filling process, the 
pressure between the bottle and the pressure tank is equalized so that the 
liquid is discharged into the bottle by the force of gravity. During the 
filling process the counterpressure gas taking place in the bottle is 
exchanged for the discharged liquid and returned into the gas space in the 
tank. For this purpose a gas-return pipe is used whereby the position of 
its opening in the bottle determines the level of the charge and limits 
the rate of the filling process as soon as the liquid reaches the outlet 
opening and the exchange of the gas from the bottle back into the liquid 
tank is no longer possible. In known filling units of this type the danger 
exists that an amount of gas taking place above the liquid level might 
bubble up through the still open liquid discharging channel and cause a 
supplemental discharge of the liquid retained above the valve seat in the 
liquid discharging channel. In order to avoid this shortcoming, it has 
been devised to make the valve for the liquid in the form of a siphon by 
providing the valve plunger with a bell-shaped stopper the downwardly 
projecting bell-like rim portion of which is immersed into sealing liquid 
retained in a siphon channel. Apart from a minor decrease in efficiency of 
the filling system, this siphon-like embodiment has the disadvantage that 
both the annular groove forming the siphon channel and the bell-shaped 
stopper have to be made relatively long to be deeply covered by the 
liquid. The reason for this extended structure is that the bell-shaped 
stopper always moves together with the plunger of the liquid discharging 
valve between the closing and opening position of the latter. Due to the 
fact that the siphoning effect is needed mainly in the open position of 
the valve, the bell-shaped stopper has to be so long that also in this 
open position it is sufficiently immersed in the sealing liquid in the 
siphon groove. Another disadvantage of this known embodiment results also 
from the fact that due to the different depth of immerging of the 
bell-shaped stopper according to the difference in opening position of the 
valve, there result variations in the cross-section of the liquid 
discharging passage and these pg,4 variations in turn case different 
levels of charge in the bottle. In addition, the continuously changing 
position of the stopper and the resulting continuous change of boundary 
layers of the liquid prevent constructional measures that in view of 
surface tension of the discharged liquid would be desirable for increasing 
the cross-section of the liquid discharging passage. 
SUMMARY OF THE INVENTION 
An object of this invention is therefore to overcome the disadvantages of 
prior art filling units of the above-described type. 
More particularly, an object of this invention is to provide an improved 
filling unit having siphon closure means that have minimum height. 
Another object of this invention is to provide a siphon closure that serves 
also for guiding a centrally arranged and axially reciprocable valve tube 
of the gas return conduit without effecting the depth of immersion of the 
bell-shaped stopper and without disturbing the filling process. 
Still another object of this invention is to avoid turbulences in the 
discharged liquid resulting from sealing liquid present in the siphon 
groove or channel. 
Still another object of this invention is to insure maximum cross-sectional 
area of the liquid discharging passage. 
In keeping with these objects, and others which will become apparent 
hereafter, one feature of the invention resides, in a filling unit 
operating without filling pipe in the bottling machine of the 
above-described type, in a combination which comprises a stationary 
bell-shaped stopper that is secured in position in the liquid discharging 
passage by means of radial projections or supporting arms, the bell-shaped 
stopper having a central boring for guiding the axially movable valve tube 
and means for securing the valve tube against rotation about its axis and 
the lower bell-shaped portion of the stopper at least in the range of 
immersion in the sealing liquid in the siphon groove being provided with 
vertically and radially directed slits. The outer surface in the lower 
range of the bell-shaped stopper portion has a substantially cylindrical 
shape that, above the siphon groove in the range of the valve seat of the 
liquid discharging passage, gradually tapers upwardly. The central boring 
of the stopper is cylindrical to guide slidably the axially reciprocable 
valve tube; an axial groove in the boring guides a corresponding key or 
projection in the valve tube to prevent rotation of the valve tube about 
its axis. 
It is advantageous when the lower part of the bell-shaped stopper has an 
increased inner diameter to form a stop surface for the sealing disc of 
the valve tube. 
Due to the immobile arrangement of the bell-shaped stopper and because of 
the fact that the stopper is kept immersed in the siphon groove at 
constant depth, the height of the stopper can be substantially reduced. 
Consequently, the aforementioned disadvantages of prior art movable 
stoppers resulting from continuously changing conditions of the discharge, 
are avoided. At the same time, the weight of the valve tube is due to the 
reduced size of the stopper considerably reduced and the biasing spring 
lifting the valve tube in axial direction can operate with a smaller 
biasing force which in turn brings the advantage that sensitive starting 
and closing action of the valve is achieved. In addition, in the 
arrangement of the bell-shaped stopper according to this invention it is 
possible to provide an increased cross-section of the discharge passage 
without permitting the escape of the gas that otherwise would result due 
to the interface changes in the flow of the liquid caused by the upward 
and downward movement of the valve tube or piston. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS: 
The filling unit illustrated in connection with a liquid tank of a bottling 
machine rotatable about axis 9 includes a valve body 1 connected to the 
bottom of the liquid tank and communicating with the interior of the tank 
through a liquid discharging tube. The central passage of the valve body 1 
is shaped to form a valve seat 13 for cooperating with the piston disc of 
axially movable valve tube 2. The valve tube 2 is guided for reciprocal 
movement in fixedly mounted bell-shaped stopper 4 that together with an 
annular groove 3 provided in the valve body 1 forms a siphon closure for 
the liquid being discharged through the liquid discharging channel into a 
bottle. The bell-shaped stopper 4 is secured in position in the liquid 
discharging passage in the valve body 1 by means of radially projecting 
supporting arms; the center boring of the stopper serves, as mentioned 
above, for guiding the tubular piston or valve tube 2 of the liquid 
discharging valve whereby the central passage of the tube 2 acts as a gas 
return conduit. By this arrangement the guides that in prior art filling 
units of this type were necessary for stabilizing the valve tube 2 and 
cause reduction of the cross-sectional area of the liquid passage, can be 
dispensed with. The bell-shaped stopper 4 has only a recessed keyway 6 
provided in the wall of its central boring for guiding a corresponding 
projection 7 in the valve tube 2 that prevents the valve tube from 
rotation. 
According to this invention, the bell-shaped stopper 4 has on its lower 
part a plurality of vertically and radially directed slits 8 formed 
throughout the lower wall 4' so that the lower part of the stopper has a 
comb-like configuration. This arrangement allows pulp fibers that during 
the liquid discharge deposit on the surface of the upper part of the 
stopper to be rinsed down into the slits 8 and therefrom rinsed away. The 
width of the slits 8 is preferably in the range of 0.4 to 0.8 millimeters, 
and the same range of sizes have the teeth or prongs between the slits. 
The number and/or the width of the slits 8 on the periphery of the stopper 
4 can vary according to the type of the bottling machine used and can be 
larger on the adverse side 10 relative to the axis of rotation 9 than on 
the side 11 facing the axis of rotation. In this manner it is possible to 
increase the efficiency of the filling unit by amplifying the streaming of 
the liquid by force components resulting due to the rotation of the 
bottling machine. 
The outer surface 12 of the stopper 4 as mentioned above, has a bell-like 
shape which at the lower part of the stopper approximately at the level of 
the valve seat 13 is substantially cylindrical and the upper part of which 
tapers upwardly. The central boring in the upper part of the stopper 
serves for guiding the valve tube 2 and has an axial guiding groove 6 for 
receiving a guiding projection 7 on the valve tube 2. The axial boring on 
the lower part of the stopper is increased in diameter to form a stop face 
or surface 14 for limiting the maximum stroke of the piston disc of the 
reciprocal valve tube 2. The lower part of the stopper that is provided 
with the comb-like slits projections about 1 to 11/2 millimeter into the 
annular groove 15 of the siphon closure and does not change this position 
so that exactly definable flow conditions of the liquid are maintained. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
filling unit for rotary bottling machines, it is not intended to be 
limited to the details shown, since various modifications and structural 
changes may be made without departing in any way from the spirit of the 
present invention.