Abstract:
A sanitary fill tube assembly includes a pair of large diameter fill tubes connected to a spreader having a rotary valve system mounted therein. The rotary valve system is actuated by pairs of actuator arms guided through openings in a manifold connected to the fill tubes to precisely move the rotary valve between open and closed position. The rotary valve includes elongated openings therein which are closely matched with and connected to the same size and shape passageways and discharge openings in the spreader so as to more accurately control and meter material being fed into a pouch, and to maintain the overall assembly in a sanitary condition.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to fill tubes for use in pouch packaging machines, and more particularly, to a fill tube and rotary valve assembly for more accurately controlling the flow and dispensing of viscous material through and from the fill tube, in a sanitary manner. 
     2. Description of Related Art 
     Because of technical advances in pouch forming and filling machines, more and more food and other viscous products can be dispensed in product pouches as opposed to cans and bottles. Certain products, however, are very difficult to package in pouches, and/or must be treated very carefully to maintain sanitary conditions and prevent contamination. 
     The fill tubes, in most prior pouch packaging machines, are nothing more than a hollow tube which may be formed so as to take the shape of a pouch to be filled. Other fill tubes may be comprised of circular or oval tubes having a plunger rod with a bulbous valve at the end thereof, for the control of the velocity of discharge of product from the fill tube. One such prior art fill tube and plunger rod assembly for a pouch packaging machine is shown in U.S. Pat. No. 5,097,993 to W. A. Lane, Inc., the predecessor in interest of Winpak Lane, Inc., the assignee of the present invention. 
     It has been particularly difficult to package products having particulate matter therein, for instance, cheese, in a sanitary manner. The known fill tubes must be constantly cleaned, and after sustained use, replaced. Additionally, because some products have large pieces of solid product in them which must be placed in large pouches, large fill tubes must be used. This normally prevents the use of circular and/or open-end fill tubes. To overcome the problem of dispensing products, such as cheese, in prior art devices, the discharge end of the fill tube is provided with a head having a plurality of small orifices formed therein. However, the small orifices do not always work correctly and tend to become blocked or clogged, thus causing pouch filling and sanitary problems. Therefore, there exists a need in the art for an improved sanitary fill tube and control valve means for a pouch packaging machine. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide an improved filling means for a pouch packaging machine. It is a particular object of the present invention to provide an improved fill tube and control valve arrangement for a pouch packaging machine. It is a still more particular object of the present invention to provide an improved fill tube assembly having a plurality of substantially circular fill tubes controlled by a single valve means. It is yet another more particular object of the present invention to more accurately control the flow of viscous material from a pair of fill tubes into a pouch. It is a further particular object of the present invention to provide an improved rotary valve mechanism for use with a plurality of fill tubes to control the flow of a viscous material into a pouch being formed in a pouch packaging machine. 
     In accordance with one aspect of the invention, there is provided at least one substantially circular fill tube having a rotary control valve mechanism at the discharge end thereof. The rotary control valve mechanism is held in an opening in a spreader means at the discharge end of the fill tube. The rotary control valve mechanism has at least one opening therein, for alignment with at least one fill tube. 
     In a preferred embodiment of the invention, there are two fill tubes and the rotary valve assembly is a cylinder having a pair of elongated, elliptical passageways formed therethrough, for alignment with the two fill tubes, and means at each end of the cylinder connected to push rods, which push and/or pull rods rotate the rotary valve assembly between open and closed positions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of a preferred embodiment of a fill tube and rotary valve assembly of the present invention; 
     FIG. 2 is a sectional view taken along line 2--2 of FIG. 1; 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 2; 
     FIG. 4 is a sectional view taken along line 4--4 of FIG. 2; and 
     FIG. 5 is a sectional view, similar to that of FIG. 4, showing the rotary valve turned to a closed position, with viscous material held in the fill tube, above the rotary valve. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide for an explanation of a sanitary fill tube and control valve assembly for use in a pouch packaging machine for filling packages with a viscous material, such as cheese. 
     Fill tube and plunger rod assemblies for form, fill and seal pouch packaging machines are well known. One such fill tube assembly having a plunger rod assembly therein is set forth in U.S. Pat. No. 5,097,993 which is assigned to the assignee of this invention. The disclosure of this patent is herein incorporated by reference with respect to the features of form, fill and seal pouch packaging machines and the actuating mechanism for the plunger rod assembly and fill tube. 
     Normally, in form, fill and seal pouch packaging machines, sheets of plastic are fed to a station where they have side seals and a bottom cross seal formed therein. Product is then discharged into the partially formed pouch by means of a fill head or fill tube. The machine is then indexed, and a top seal formed to seal the pouch and the pouch is cut off, to complete the cycle. The machine is then cycled to form further pouches. A plurality of side by side pouches may be formed in such form, fill and seal packaging machines, in a manner well known to those skilled in the art. 
     The present invention is directed to large fill tubes and a control valve having a rotor cut off therein, for use in form, fill and seal pouch packaging machines. For clarity of understanding, only a double fill tube assembly, including a spreader and a rotating rotor cut off system, is shown on the drawings and described herein. 
     Turning now to the drawings, there shown is a fill tube assembly 10 including a pair of large diameter fill tubes 12, for example, 3&#34; outside diameter seamless stainless steel tubes having a wall thickness of approximately 0.065 inches. Each of the fill tubes 12 has its lower end sealing secured in or to a pouch spreader 14. A pouch is formed around the spreader 14, in a manner well known to those skilled in the art. A substantially cylindrical valve means or rotor 16, having a pair of elongated or oval openings or passageways 18 extending therethrough, is rotatably held in the spreader 14. The rotor 16 also includes a pair of offset apertures 20 extending therethrough, along the length thereof between ends 30. A pair of actuator rods 22 are secured to each end 30 by means of elongated rods 24, which may be threaded at both ends, inserted in and extending entirely through the apertures 20, so as to protrude beyond each end 30. The actuator rods 22 are then secured to opposite ends 30 of the valve rotor 16 by means of the elongated rods 24 and holding means, such as nuts and washers 26. For example, the threaded ends of the rods 24 may extend through openings 28 formed in the lower end of each actuator rod 22, and be secured by the nuts 26 to each end 30. 
     The cylindrical valve rotor 16 is easily and quickly inserted in and held in an opening 32 formed perpendicular to the fill tubes 12, extending across spreader assembly 14. The rotor 16 is preferably provided with a pair of O-ring seals 34 held in cavities 36 formed on opposite ends of the rotor to sealingly hold the rotor in opening 32. The spreader 14 may include a pair of outer ears of wings 35 for securing the fill tube and valve assembly in a desired position in a form, fill and seal packaging machine. 
     The other or upper ends of the fill tubes 12 are sealingly secured to a fill tube plate or manifold 38. This manifold or plate 38 has a pair of circular apertures 40 therein, aligned with the circular interior of each fill tube 12. Plate 38 is in turn, connected to a hopper or reservoir, a feed pump system, and other conduits and tubes, as needed, to enable viscous product to be introduced into the fill tubes 12 through the openings 40. 
     As shown more clearly in FIGS. 2-5, the pouch spreader assembly 14 includes an outer skirt 37 to shape the pouch being filled, and a plurality of inner passageways 41 having slanted or slopped walls 42, to form substantially funnel shaped openings. The circular interior of the fill tubes 12 is connected to the passageways 41 in spreader 14 which direct viscous food product 44 (see FIG. 5), against sloped walls 42, and down toward smaller, elongated apertures 46, formed adjacent the rotor 16. These elongated apertures 46 are aligned with, and are preferably the same size and shape as the oval passageways 18 formed through the rotor 16. Additionally, a lower or end wall 48 of the spreader 14 includes a pair of discharge or exit apertures 50, also preferably aligned with and the same size and shape as the oval passageways 18, to allow viscous product to be discharged from the spreader 14 into a partially formed pouch around the spreader (not shown). This system allows a pouch around the spreader to be filled with a predetermined amount of product. 
     As best shown in FIGS. 2 and 3, in addition to the internal slanted walls 42, the passageways 41 in the upper portion of the spreader 14 include substantially straight inner walls 52, toward the central portion of the spreader. These inner walls 52 allow the elongated openings 18 and mating oval apertures 46 to be offset, toward the center of the spreader, where they are aligned with an inner wall of each of the fill tubes 12, to more accurately and precisely control the flow of viscous product from the fill tubes 12 through the openings 41, aligned oval openings 18 and out through the oval discharge openings 50, to fill a pouch. 
     As best shown in FIG. 1, the actuator rods 22 are inserted into and guided by a pair of slots 39 formed in plate 38. The outer ends of the actuator rods 22 are connected to and reciprocated by a hydraulic, pneumatic, or mechanical drive system, such as a reciprocating shaft and hub assembly means (not shown). Such a drive system would reciprocate the rods 22, to partially turn the rotor valve 16, in the direction of arrow 54 (see FIG. 5) between the fully open position (FIGS. 2 through 4) and the fully closed position (FIG. 5). That is, with the actuator rods 22 inserted through the guide slots 39, and with the openings 28 of a pair of actuator rods connected to each end 30 of the rotary valve 16 via the elongated rods 24 and securing means 26, the actuator rods 22 at each end 30 may be alternately moved or reciprocated, in the direction of arrow 56 (FIG. 5), to smoothly rotate the rotor 16 between the open and closed positions. 
     It is to be understood that the entire fill tube and valve assembly described herein is preferably formed of stainless steel or other materials which may be easily assembled together and sealed, in such a manner that there will be no galling and so as to be easily cleaned. The parts of the present invention are accurately formed with very close tolerances and assembled so that a minimum of seams or openings are formed where viscous food product, such as cheese or the like, could catch or stay. All of the components of the present invention are sized and dimensioned so as to be easily cleaned and assembled with accurate and tight fits, to provide the most efficient and sanitary fill tube and valve control mechanism possible. 
     In operation, viscous material is fed into each fill tube 12, through the aperture 40, and travels down the fill tubes until it reaches the passageways 41 at the top of spreader 14. If the actuator rods 22 have been reciprocated so as to close the rotor valve, as shown in FIG. 5, the viscous food product will remain in the fill tubes and passageways 41 (see FIG. 5). However, if the actuator rods have been operated to rotate the rotor valve 16 to the open position with the openings 18 aligned with the same size apertures 46 and 50, viscous food product will be fed from discharge opening 50 into a pouch, surrounding the spreader 14, until a predetermined amount, by weight or volume, is held in the pouch. A feed pump mechanism and the form, fill and seal packaging machine will then cycle so as to cut off flow of product, to seal the pouch, and then to cut off the just filled pouch. Another partially formed pouch may then be brought into position so as to be accurately filled by the double fill tube assembly and rotary valve mechanism of the present invention. 
     Accordingly, as should be apparent to those skilled in the art, the present invention provides considerable advantages in the control and feeding of viscous food matter, such as cheese or the like, into flexible plastic pouches in a sanitary manner. The double fill tube assembly of the present invention includes a rotary shut off valve means that swiftly and cleanly shuts off the flow of viscous fluid therethrough, without any wastage. Furthermore, since the rotary shut off valve of the present invention is operated by pairs of actuating rods secured to each end thereof, the rotary valve may be more accurately and precisely controlled to thereby more accurately fill pouches and precisely cut off the flow of viscous product to a filled pouch, thereby avoiding wastage and contamination. 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments may be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.