Filling element for counter pressure filling machines

[57] ABSTRACT

A filling structure free from filling pipe means for counter pressure filling machines. A gas conduit extends coaxially from a tubular fluid discharge opening into a pressed-on vessel to be filled with liquid. The gas conduit has an opening for discharging the tension gas and limiting the drop height. The gas conduit is equipped with an electric control adapted to be influenced by the substance to be filled in for releasing a closing pulse for a liquid control valve.

Claims, 2 Drawing Figures

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3.779,293

PATENTED Mt 18 ira

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3,779,293

FILLING ELEMENT FOR COUNTER PRESSURE FILLING MACHINES

The present invention relates to a filling element for counter-pressure filling machines and, more specifically, concerns a filling element of this type which has no filling pipe and comprises one or more chambers. Such filling element has a gas conduit which extends coaxially from a tubular fluid discharge opening into a pressed-on vessel. The gas conduit on the side of the vessel has an opening for discharging the tension gas and limiting the drop height. The gas conduit is furthermore equipped with an electric control device, adapted to be influenced by the substance to be filled in, for releasing the closing impulse for the liquid control valve.

With filling elements of the above-mentioned type, the conduit end located at the vessel side is provided with an opening and is customarily designed as a detachable pipe section. When the gas access to this pipe section which is identical with the gas conduit is interrupted by the rising liquid level, also the inflow of the liqud ends. The pipe section in most instances is additionally equipped with a rejecting shield for the inflowing liquid. This simultaneously results in functions as a limiting device for the filling quantity so that the liquid control valve is closed at a later time and subsequently the relief valve is opened. The control movements for these valves are customarily initiated by common abutment element which have to be adjusted when vessels of different sizes are processed.

With filling elements which do not have a filling pipe and which are equipped with electrically controllable liquid control valves, it has become known by U.S. Pat. No. 3,443,608 Copping et al. issued May 13, 1969 to determine the filling height in the pressed-on vessels by means of an electric control member adapted to be introduced into the vessels. Influenced by the filling substance rising to the predetermined filling height, the control member initiates the impulse for the closing movement of the liquid control valve. The control member associated with each element at that end of the gas conduit which is located on the vessel side is mounted below the conduit opening which serves merely for withdrawing the tension gas and remains outside the region of the rising filling substance. Thus, the control members replace the common abutment elements mentioned above and customary with mechanically controlled filling elements.

Experience has shown that with arrangements of the last mentioned type, at high filling speeds especially with vessels having a narrow neck, a uniform filling height can in most instances not be realized. This is due above all to the inertia inherent to the complicated structure of the liquid control valves and the control elements therefor. The inherently different length of closing periods following the impulse being emitted by the control member result in permitting noncontrollable quantities of filling substance can flow into the vessels consequently different height of liquid levels occur below the mouths of the vessels. With the known filling elements it is also unfavorable that the control element is arranged at that end of the gas conduit which is located on the vessel side. Thus the control member is not protected against damage which may occur above all when the control member is introduced into a poorly centered vessel or when a vessel breaks, especially during the tensioning process.

It is therefore, an object of the present invention to provide a filling element which will overcome the above mentioned drawbacks.

This object and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a longitudinal section through a filling element according to the invention.

FIG. 2 is a section taken along the line II—II of FIG. 1.

The filling element according to the present invention which does not have a filling pipe is characterized primarily in that the control member is located in the path of the gas above the opening of the gas conduit. According to a further development of the invention it is suggested to make the control member adjustable as to height and to provide it with an adjusting device associated with the filling element. In view of the design according to the invention, according to which the gas conduit determines the filling height in the pressed-on vessel, whereas the control element controls the liquid control valve and, if desired, initiates or releases the relief valve and further control functions, the additional advantage is obtained that by means of the suggested height adjustment of the control member, the control period for the closing movement of the liquid control valve can be selected freely.

According to the present invention it is further suggested to connect the control member to that end of a shank which is located on the vessel side and which is vertically guided in the interior of the element and has that end which is located opposite the control element connectable to the adjusting device. To this end, the adjusting device advantageously comprises a threaded sleeve with a manually operable handwheel mounted thereon to which the shank end is coupled. The threaded sleeve is vertically connected to the element housing or is connected to an element detail which protrudes from the element housing.

Referring now to the drawings in detail, of the onechamber counter-pressure filling machine involved, merely the filling container 10 for the liquid and tension gas and the lifting element 11 with a dish-shaped surface 12 are shown. Opposite each lifting element 11 there is provided a filling element 14 which is flanged to the container 10. The filling element 14 is connected through separate gas and liquid inlet means 15 and 16 to corresponding outlets of the container 10 in a gastight and liquid-tight manner. The gas inlet 15 is designed in the manner of a connection adapted to be plugged into the container outlet.

At that end which is adjacent the container or vessel 13 the element 14 has a valve seat 18 within the housing. The valve seat together with a valve body 20 supported by said valve seat and provided with a seal 17 forms the liquid control valve 18, 20. This liquid control valve, when in open condition, forms a gas barrier in the form of a labyrinth. A central bore 19 extends through the valve body 20 and is provided with a thread 21 within the region of the seal 17. Screwed onto the thread 21 is a gas pipe 23 with an opening 22. Pipe 23 with bore 19 forms the gas conduit 19, 23. The gas pipe 23 itself is provided with a rejecting shield 24.

Below the liquid valve 18, 20 and below the valve seat 18 there is provided a liquid discharge member 25 which is of tubular shape and through which the gas

3,779,293 conduit 19, 23 extends coaxially. The liquid discharge member 25 is surrounded by a centering tulip 27 provided with a rubber insert 26 and adapted to be lifted and lowered. A switch 28, expediently an approximation switch, or proximity limit switch extends into the stroke range of the tulip 27, From the liquid discharge member 25, a passage 29 leads to a magnetic valve 31 which is connected to the housing extension 30, preferably in screwed thereinto, and communicates with the passage 29.

As will be seen from FIG. 2, valve 31 has a valve body 33 which is longitudinally movable in a valve chamber 32. Valve body 33 is located opposite a bore 35 provided with a seat 34 and leading to the passage 29. The force exerted by the spring 37 acts in a direction counter to the force exerted by the magnet 36. The valve chamber 32 communicates with the atmosphere through a coaxial bore 38 in the valve body 33. The bore has an exit opening 39 leading to the chamber 32 and through a bore 40 provided in the valve housing 31 and leading into the atmosphere. Bore 40 is expediently provided with a throttle area 41 and at its exit is provided with a hose nipple 42.

As has been shown in FIG. 1, the valve body 20 extends vertically in the element housing 14. The valve body 20 has its upper end portion located opposite the seat 18 and widened so as to form a collar 43. The valve body 20 is longitudinally guided in a housing bore 44 by means of the collar 43. One end of a spring 45 rests against the collar 43 whereas the other end of spring 45 rests against a shoulder 46 of filling element 14. Opposite an extension 47 provided on the upper end of collar 43 there is located an approximation or proximity limit switch 49 connected in housing 14. There is furthermore located a housing abutment 50 for limiting the upward stroke of the valve body 20. Valve body 20 rests by means of the extension 47 against a seal 48 located in the housing bore 44. Below the extension 47, the collar 43 is preferably provided with a restriction 51 which tapers conically in downward direction within the region of the seal 48. Coaxially provided within the collar 43 is a pot-shaped recess 52 having a diameter which is larger than the diameter of the lower portion of the body 54. Provided on the plane bottom surface of the recess 52 is a valve seat 53 for the body 54 which forms a valve body in the form of a tubular section. Valve seat 53 and valve body 54 together form the tension gas valve 53, 54 for which the valve body 20 of the liquid control valve 18, 20 forms the supporting element. The upper end of the valve body 54 forms a piston 55 which extends into a chamber 58 of a magnetic valve 59. The chamber 58 is provided with inlet openings 56, 57. The upper end of piston 55 which protrudes from the housing 14 is provided with a threaded sleeve 62 which is connected to the piston 55 by means of a clamping nut 61. Sleeve 62 has longitudinal slots which are located in the sleeve walls opposite to each other and has its outer thread in engagement with a handwheel 64 provided with an inner annular groove 63.

A shank 65 extends through the vertically arranged sleeve 62, the piston 55 and the tension gas valve body 54 and has its lower end extend into the gas conduit 19, 23. The lower end preferably is offset within the tension gas valve body 54. This shank end which is sealed relative to the valve body 54 by means of a seal 60 has connected thereto an electric control member 66 adapted to be controlled by the filling substance. The control means (not shown in detail) of control member 66 are provided on a card 67 which is exchangeably connected to the vessel or container 10. The conductor leading from the control member 66 to the card 67 is designated with the reference numeral 68. At the opposite end of the control member 66, the shank 65 is coupled to the handwheel 64 by means of a bolt 69 extending through the slots of sleeve 62. Counter nuts 70 secure the bolt 69 vertically arranged on an extension of the shank. The end of bolt 69 extend into the annular space 63 of the hand-wheel 64.

The operation of the device is as follows:

When the magnetic valves 31 of the elements 14 are closed and the control members 66 of all filling elements 14 have been individually and manually set by means of the control wheels 64 for the required level in the gas conduits 19, 23, and when the machine has been turned on operation proceeds. By means of a customary feeding turnstile, the vessel will be moved onto the lifting members 11, 12. In this connection it is advisable to arrange the control members 66 directly below the tension gas valves 53, 54. This assures that the gas spaces which form in the gas conduits 19, 23 below the valves 53, 54 will with the rising liquid remain small. Thus the contents of the vessel will not be disquieted when the pressure is reduced to atmospheric pressure. In the course of the starting upward movement of the lifting members 11, 12, it will be appreciated that when considering an individual filling element 14, first the centering of the vessel 13 by the tulip 27 will be effected while the gas pipe 23 is introduced into the vessel 13. In the course of the further upward stroke of the vessel, the tulip 27 will engage the lower side of the housing. In this position, the vessel 13 will be pressed against the rubber insert 26 in the tulip 27.

The switch 28 during the upward stroke of vessel 13 is influenced by the centering tulip 27. Through the intervention of the control means on card 67, the switch 28 will actuate the magnetic valve 59 which opens the inlet 56 to permit the liquid to flow into the chamber 58. With started upward movement of the piston 55 the bottom side of which is subjected to fluid pressure, the valve body 54 is lifted off the seat 53 so that tension gas will pass into the pressed-on vessel 13 from the filling container 10 through conduit 15, recess 52, the opened tension gas valve 53, 54 and the gas conduit 19, 23.

When approximately equilibrium has been established between the tension gas pressure in the pressedon vessel 13 and in the filling container 10, spring 45 opens the liquid control valve 18, 20. The upwardly moved valve body 20 will have its extension 47 engage the adjustable abutment 50 while the tension gas valve 53, 54 remains open. In the course of the upward movement of the valve body 20, the extension 47 furthermore influences the approximation or proximity limit switch 49. Through the control means of card 67, the switch 49 brings the control member 66 into readiness. The filling substance now flows through the opened liquid control valve 18, 20 and the labyrinth and furthermore the outlet 25 and over the rejecting shield 24 into the vessel 13. The displaced tension gas passes through conduit 19,23, the opened valve 53,54, the recess 52 and the conduit 60 back into the gas chamber of the filling vessel 10.

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When the rising liquid level reaches the opening 22 of the gas pipe 23, the filling substance cuts off the return gas path, and the admission of liquid is interrupted. The liquid level now with a quieted surface rises in the gas pipe 23 and subsequently in bore 19 reaches the control member 66 above the vessel 13. The control member 66 now influences the control means of card 67 associated with the magnetic valve 59. The valve 59 is now again actuated and closes the inlet 56. This establishes communication with the atmosphere and simultaneously opens the inlet 57 to the piston chamber 58. The fluid medium up to this point via inlet 56 acts continuously upon the bottom side of piston 55 and keeps the valve body 54 in its opened position. Now the fluid medium actuates the top side of piston 55 via inlet 57 whereby the valve body 54 is moved back to the seat 53. Subsequently also the valve body 20 is returned to its seat 18 so that the tension gas valve 53, 54 and the liquid control valve 18, 20 are closed. The magnetic valve 31 is actuated by the control member 66 after the expiration of a selected delaying time. The magnetic valve 31 changes the location of its valve body 33 and thereby opens the bore 35 which communicates through passage 29 with the outlet 25. As a result thereof, the gas spaces communicating with the pressed-on vessel 13 will lose their tension through gas paths 32, 39, 38, 40 and the throttle area 41 of the magnetic valve 31 and will assume atmospheric pressure. When subsequently the vessel 13 is withdrawn from the filling element 14 by lowering the lifting element 11, 12, the tulip 27 again occupies its starting position. The tulip 27 then moves out of the range of the approximation or proximity limit switch 28. Through the control means of the card 67, the switch 28 interrupts the current to the magnetic valve 31. In view of the influence of spring 37, the valve body 33 of valve 31 closes the passage 29.

If it should happen, for instance, that in a damaged vessel no or only a minor tension gas pressure is built up, the liquid control valve 18, 20 retains its closing position, and the extension 47 of the valve body 20 does not pass into the region of the approximation or proximity limit switch 49. The control impulse previously was initiated by the approximation or proximity limit switch 28. Thus in the manner described above the magnetic valve 59 was caused to open the inlet 56 and the tension gas valve 53, 54 was opened by the fluid medium. This control impulse is extinguished after a predetermined time while the magnetic valve 59 is deenergized. The fluid medium which subsequently through inlet 57 acts upon piston 55 returns the latter to its starting position whereby the tension gas valve 53, 54 is closed.

It is, of course, to be understood that the present invention is, by no means, limited to the particular structure shown in the drawings but also comprises any modifications within the scope of the appended claims. Furthermore, even though the invention has been described in connection with one-chamber filling elements, it will be appreciated that it is also applicable to multi-chamber filling elements which do not have filling pipes and that for such filling elements the same arrangement of the control member in the gas path opposite the opening of the gas conduit is intended.

It is also to be understood that the control member 66 which by means of the pulse controlling the closing movement of the valve body 20, also controls the clos6 ing movement of the magnetic or relief valve 31 may also control additional operations in the filling structure according to this invention.