Abstract:
A vacuum packaging machine ( 10 ) is provided having a base ( 12 ) and a pivotally mounted lid ( 14 ) which cooperatively define a package air evacuation chamber ( 76 ) adapted to receive the open end ( 98 ) of a filled flexible package ( 100 ), thereby allowing evacuation of air from the package ( 100 ) and heat sealing of end ( 98 ). The machine ( 10 ) is characterized by an essentially flat and interrupted, easily cleanable base upper wall ( 28 ) which eliminates concavities in the like which can lead to unsanitary collection of fluids or solids. The machine ( 10 ) also has a vacuum source ( 16 ) and a vacuum conduit assembly ( 18 ) the latter having conduits within base ( 12 ) and lid ( 14 ).

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is being filed contemporaneously with application for U.S. Design patent Ser. No. ______, entitled VACUUM PACKAGING MACHINE, which is hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention is broadly concerned with packaging equipment. More particularly, the present invention concerns a vacuum packaging machine of the type used for the purpose of creating evacuated and sealed packages of food.  
         [0004]     2. Description of the Prior Art  
         [0005]     It is known to provide a vacuum packaging apparatus for use in evacuating the air in an open-ended package and sealing the evacuated package. A typical apparatus of this type presents a chamber sized only for receipt of the open end of the package with the remainder of the package disposed outside of the chamber, and a vacuum pump communicating with the chamber for evacuating the chamber and the package through the open end. The sealing mechanism may include a heating element disposed outside the vacuum chamber and extending along the front of the base beyond the ends of the vacuum chamber. The heating element in this design is fixed to the base so that when the lid is lowered onto the base, the heating element is pressed against a portion of the package external of the chamber. Upon evacuation of the package, current is delivered to the heating element, melting the package material to seal the package closed.  
         [0006]     U.S. Pat. No. 5,638,664 discloses an improved packaging apparatus which eliminates the problems inherent in the above types of vacuum packaging devices. The &#39;664 patent has a package sealing element located within a concavity formed in the base, and is entirely within the confines of the evacuation chamber. However, the design also makes use of a liquid trap in the form of an elongated channel rearward of the sealing element, as well as a forward resilient member serving as a part of the vacuum seal. This base design can present problems in that the trap and seal arrangement collects liquids or other food particles and thus can be unsanitary if not cleaned on a regular basis. Furthermore, this patented design employs an elongated inflatable bladder beneath the resistance heating element which is inflated in timed relationship to air evacuation from a package. This bladder is directly coupled with the vacuum pump of the unit and thus is a closed part of the system.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a greatly improved vacuum packaging apparatus or machine especially designed for household consumer use. With respect to a first aspect of the present invention, the vacuum packaging machine includes a base presenting an upper package end-supporting surface, and a lid operatively coupled with the base and having a lower surface. The lid is movable between an open position permitting placement of the package open end upon the base upper surface, and a closed position where the base upper surface and lid lower surface are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. The machine also includes a vacuum source and an evacuation port in communication with the chamber. The evacuation port is operatively coupled with the vacuum source in order to evacuate the package through the open end. The machine further includes a sealing component proximal to the chamber and operable to seal the open end after evacuation of the package. Moreover, the upper package end-supporting surface of the base in the area thereof bounded by the chamber presents a readily cleanable, essentially flat surface free of concavities. The portion of the base within the confines of the evacuation chamber is consequently substantially flat and interrupted, and free of slots or other concavities which can collect fluids or solid food particles and lead to unsanitary conditions. That portion of the base can simply be cleaned by wiping it with a cloth (preferably utilizing also a sanitary cleaning fluid).  
         [0008]     Another aspect of the present invention concerns a vacuum packaging machine including a base and a lid operatively coupled with the base. The lid is movable between an open position permitting placement of the package open end between the lid and base, and a closed position where the lid and base are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. A vacuum source is provided within said base, and an evacuation port in the lid is in communication with the chamber. The machine further includes a sealing component proximal to the chamber and operable to seal the open end after evacuation of the package. Yet further, the machine includes a conduit assembly operatively coupling the evacuation port with the vacuum source in order to evacuate the package through the open end. The conduit assembly includes a first conduit extending from the evacuation port to a connection port on the lid outside the boundaries of the chamber, a second conduit within the base extending from a connection port on the base outside the confines of the chamber and coupled with the vacuum source, and sealing structure between the lid and base connection ports affording a seal between the connection ports when the lid is in the closed position thereof.  
         [0009]     A third aspect of the present invention concerns a vacuum packaging machine including a base and a lid operatively coupled with the base. The lid is movable between an open position permitting placement of the package open end between the lid and base, and a closed position where the lid and base are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. The machine also includes a vacuum source, as well as an evacuation port in communication with the chamber and operatively coupled with the vacuum source in order to evacuate the package through the open end. The machine further includes a sealing component proximal to the chamber and operable to seal the package open end after evacuation of the package. The sealing component includes an elongated expandable bladder having the interior thereof vented to the atmosphere, and a resistance heatable sealing element disposed above the bladder. The base presenting a housing in which the bladder is located, and the vacuum source is operatively coupled with the housing for inducing negative pressure conditions therein. The bladder is operable, under the influence of induced negative pressure conditions within the housing, to expand and shift the sealing element towards the chamber for sealing of the package open end.  
         [0010]     Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0011]     Preferred embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:  
         [0012]      FIG. 1  is a perspective view of a vacuum packaging machine in accordance with the invention;  
         [0013]      FIG. 2  is a perspective view similar to that of  FIG. 1 , but depicting the lid of the machine in its open position;  
         [0014]      FIG. 3  is a vertical sectional view of the vacuum packaging machine illustrating the lid in a partially opened condition and depicting the internal details of construction of the machine;  
         [0015]      FIG. 4  is a vertical sectional view similar to that of  FIG. 3 , but showing the machine in use during evacuation and sealing of a package; and  
         [0016]      FIG. 5  is a front view of the vacuum packaging machine with certain parts broken away and other parts illustrated in phantom. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]     Turning now to the drawings, and particularly  FIGS. 1 and 2 , a vacuum packaging machine  10  in accordance with the invention broadly includes a base  12  and a lid  14  pivotally coupled to the base and shiftable between a closed position ( FIG. 1 ) and an open position ( FIG. 2 ). The overall machine  10  further includes a vacuum source  16  within base  12 , a conduit assembly  18  having components within base  12  and lid  14 , and a package sealing assembly  20  supported by base  12  and lid  14 .  
         [0018]     In more detail, the base  12  is in the form of a housing  22  including a bottom wall  24 , circumscribing sidewalls  26  formed to present a forward access notch  27  and a rearward, central, lid-mounting recess  27   a,  and an upper, smooth and substantially uninterrupted top wall  28 . The top wall preferably presents a package end-supporting surface  28   a  that serves to support the open end of the package during the evacuation and sealing steps. The housing  22  has a vacuum pump and control section  30  astride the lidded package evacuated and sealing section  32 . Referring to  FIG. 4 , it will be observed that projecting downwardly from the top wall  28  is an elongated, laterally extending, rectangular in cross-section bladder housing  34 . The housing presents a tubular vacuum conduit insert  35  and a venting outlet  35   a  (see  FIG. 5 ).  
         [0019]     The package sealing assembly  20  preferably includes an elongated resilient elastomeric bladder  36  seated within housing  36  with venting outlet  35   a  extending through the housing wall and into the interior of the bladder to vent bladder  36  to the atmosphere. A sponge-like, closed cell elongated sealing member  38  is located atop bladder  36 . Although the sealing member  38  is illustrated within the bladder housing  36 , the principles of the present invention are equally applicable to a arrangement wherein only the bladder is sealed within the housing (for purposes which will be described) but maintains its operable connection to the sealing member  38  to control movement thereof. An elongated resistance heatable package end sealing element  40  rests on the member  38 , and is preferably secured thereto by suitable means (such as fasteners, adhesive, etc.). It will be appreciated that a number of the components of the illustrated embodiment are similar to those disclosed in U.S. Pat. No. 5,638,664, which is hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention.  
         [0020]     The top wall  28  of the base  12  further includes an elongated strip  42  of flexible resilient material surmounting and covering the upper open end of bladder housing  34  and the components therein. The strip  42  may be formed of Teflon or other suitable material, and is adhesively secured in place in order to affect a seal over the housing while substantially maintaining the continuous and uninterrupted nature of top wall  28 . The strip is sufficiently flexible to permit movement of the sealing member (and element  40 ), as well as being sufficiently conductive to transfer heat from the element  40  to the package, when sealing of the package is affected. The top wall  28  also includes a rearward connection port  44  surrounded by a resilient annular gasket-type sealing member  46 ; the importance of this port and seal arrangement will be made clear hereinafter.  
         [0021]     The housing section  30  includes a control panel  48  having a readout  50  and appropriate control buttons  52  to initiate and control the operation of the machine  10 .  
         [0022]     Lid  14  is fabricated in the form of a housing  54  having top wall  56 , circumscribing sidewalls  58  and bottom wall  60 . A central, depending, rearmost extension  62  is secured to the housing  54  and is received within base recess  27   a.  A pivot pin  64  connected to the base serves to pivotally mount the lid  14  to base  12 .  
         [0023]     The bottom wall  60  of lid housing  54  has a rectangular stepped opening  65  therein which receives an evacuation and sealing assembly  66 . The assembly forms part of the package sealing assembly  20  and cooperates with the above-noted components in the base  12  to seal the package, as will be described. More particularly, the assembly  66  includes an apertured synthetic resin plate  68  having a tubular insert  70  aligned with an evacuation port  71 . The lower surface of plate  68  supports a generally rectangular, circumscribing resilient sealing element  72  as well as inboard, elongated, laterally spaced ribs  74 . The purpose of element  72  and ribs  74  is to form closed evacuation chamber  76  (see  FIG. 4 ) when lid  14  is closed. Finally, an elongated, resilient backing strip  75  is supported on plate  68  and is adapted to come into registry with resistance sealing element  40  when lid  14  is closed.  
         [0024]     The bottom wall  60  also has a connection port  78  therein with a rigid, annular gasket-type sealing member  80  disposed about and in registry with connection port. The port  78  is located to mate with base connection port  44  when the lid  14  is closed, and with the annular seals  46  and  80  also in sealing engagement with another. This unique arrangement provides the necessary communication between the evacuation port  71 , which is preferably located within the lid  14 , and the vacuum source  16 , which is preferably located within the base. It will be appreciated, that the sealing arrangement between the connection ports  44  and  78  could also accommodate a design in which locations of the evacuation port and vacuum source are reversed, with the former being in the base and latter being in the lid.  
         [0025]     The vacuum source  16  is preferably a conventional vacuum pump  82  having a vacuum output conduit  84  and an exhaust conduit  86  vented to the atmosphere through the bottom wall  24 . As noted previously, the pump  62  is preferably housed within section  30  of base  12 , generally below and rearward of control panel  48 .  
         [0026]     The conduit assembly  18  includes a first, generally U-shaped conduit  88  within housing  54  of lid  14 . As best seen in  FIGS. 3-5 , the conduit  88  is secured to insert  70  at one end thereof, and is connected at the other end in mating relationship with connection port  78  via coupler  90 . The overall assembly  18  further includes conduits within base housing  22 , namely a second, depending conduit  92  secured to the underside of wall  28  in registry with connection port  44  and having a T-coupler  94  at the lower end thereof. One leg of T-coupler  94  is connected to vacuum pump conduit  84 . The other leg is connected with a third conduit  96  which is secured to insert  35  to communicate with the interior of bladder housing  34 .  
         [0027]     As shown in  FIG. 1 , the machine  10  is provided with an electrical cord  97  for connecting to a conventional wall socket (not shown) to provide power to the various electrical components. It will be appreciated, however, that the principles of the present invention are equally applicable to a battery-powered machine or a machine utilizing other suitable sources for powering the necessary components.  
         [0028]     In the use of machine  10 , lid  14  is first opened, exposing the upper package end-supporting surface  28   a  defined by base top wall  28 . Next, the user places the open end  98  of a flexible bag or package  100  (see  FIG. 4 ) on the surface  28   a  generally above sealing element  40 , with the end  98  preferably being within the confines of the chamber  76  (i.e., within the area bounded by the element  72 ). The lid  14  is then closed, with sealing element  72  coming into engagement with top wall  28  and the upper ply of end  98  in order to create a substantially air tight evacuation chamber  76 . Moreover, closure of the lid  14  causes the annular sealing elements  80  and  44  to come into sealing engagement, thus communicating the connection ports  44  and  78  which are of course well outside the boundaries of chamber  76 . Furthermore, with closure of the lid  14 , the backing member  75  comes into registry with sealing element  40  beneath strip  42 .  
         [0029]     Next, the control buttons  52  are manipulated in order to first evacuate air from package  100  and then to seal the open end  98 . Alternatively, these steps may be automatically initiated by the panel  48  whenever the lid  14  is closed. In either case, the vacuum pump  82  is operated which first serves to evacuate air from package  100 . The pump  82  exhausts the air from the package through port  71 , insert  70 , first conduit  88 , connection ports  78 ,  44 , second conduit  90 , vacuum conduit  84  and exhaust conduit  86 . During this same time, a vacuum is drawn in third conduit  96  and thereby the bladder housing  34 . Because the interior of the bladder is vented to atmosphere, the negative pressure created within the housing  34  by the pump  82  serves to expand bladder  36 . It has been determined that the illustrated embodiment advantageously ensures that bladder expansion proceeds relatively slowly as compared with evacuation of package  100 , and thus the bladder expansion does not impede the desired package air evacuation. However, if necessary, the conduit assembly  18  may be provided with a flow restrictor or valve (both not shown) within the third conduit  96  to ensure such operational timing.  
         [0030]     After a predetermined time of vacuum pump operation calculated to remove substantially all air from package  100  while effecting vacuum induced expansion of bladder  36 , the formerly open end  98  of package  100  is closed. At this point the resistance heating element  40  is energized, quickly developing sufficient heat to fuse the plies of open end  98 , thus sealing the package  100 . The backing strip  75  ensures sufficient engagement (through the strip  42 ) between the element  40  and package  100  to provide the desired sealing of the open end  98 . After such sealing, the lid  14  is again opened, and the evacuated and sealed package is removed.  
         [0031]     A particular feature of the construction of machine  10  resides in provision of an essentially flat, continuous sealing surface  28  defined by part of the illustrated top wall  28 , which is entirely free of concavities or other surface features which collect fluids or solids. Thus, this upper surface is readily cleanable and more sanitary.  
         [0032]     The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention.  
         [0033]     The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.