Abstract:
A packaging machine comprising a machine stand and an insulator housing sealingly connected to the machine stand. The connection to the machine stand is made via retainers, disposed on the machine housing, with a profile frame of the insulator housing resting on the retainers. Between the insulator housing and the machine stand, a gap is formed, in which a sealing element is disposed. The packaging machine according to the invention makes standardized machine stands possible, as well as a structure that is simpler from the production standpoint, because less stringent tolerances are required.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a packaging machine, in particular for filling and sealing containers containing liquid pharmaceuticals. A packaging machine of this kind has a hoodlike insulator housing, which sealingly surrounds a machine plate of a machine stand, thus forming a sterile chamber in which the containers are filled with a product and then sealed. On its underside toward the machine stand, the insulator housing has an encompassing, inward-drawn edge, which with the interposition of a sealing element, such as silicone, rests with its full surface on the top side of the machine plate, on the peripheral regions thereof. To fix the insulator housing on the machine stand, threaded bolts are also disposed on the underside of the inward-drawn edge of the insulator housing; the bolts engage suitably disposed openings in the machine plate. A disadvantage of this is that the machine stand with its machine plate is also used in packaging machines that lack the insulator housing, so that for those applications the machine plate is unnecessarily wide, considering that for reasons of standardization it is always desirable to use the same machine plate. The openings for the threaded bolts of the insulator housing furthermore require additional production effort and expense. Especially if the machine plate has a plurality of regions of different heights, the production of the insulator housing and of the machine plate is also relatively complicated, since the height tolerances of the components must be relatively tight in order to limit the heights of the gaps. 
     ADVANTAGES OF THE INVENTION 
     The packaging machine according to the invention, particularly for filling and sealing containers containing liquid pharmaceuticals has an advantage that the production effort and expense for both the machine plate and the insulator housing are reduced, since the tolerances for the individual components can be less stringent. Furthermore, both for filling systems that use an insulator housing and filling systems without an insulator, one and the same relatively narrow machine plate can be used. Disposing the insulator housing according to the invention also makes monitoring simpler and enables easier replacement of the sealing element, since there is no longer any need to dismantle or remove the insulator housing. 
    
    
     The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawing. 
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is simplified side view of a packaging machine according to the invention for filling and sealing containers; 
     FIG. 2 is a section taken along the line II—II of FIG. 1; 
     FIG. 3 is a section in the region of the insulator housing fastening and the inspection window in the prior art; 
     FIG. 4 shows a first insulator fastening according to the invention in terms of the detail marked X in FIG. 2; 
     FIG. 5 shows a second insulator fastening according to the invention; and 
     FIG. 6 shows a third insulator fastening according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The packaging machine  10  shown in the drawings is used in the pharmaceutical industry for filling and sealing containers, such as ampules, vials or the like. The packaging machine  10  is constructed by the so-called insulator technique; that means that sterile conditions prevail in the interior  11  of the packaging machine  10 . To that end, the packaging machine  10  has a machine stand  12 , in which the essential drive components are disposed. The top of the machine stand  12  is closed off by at least one machine plate  13 , and in the exemplary embodiment shown two machine plates  13   a ,  13   b , which are disposed at different levels (see FIG.  2 ). Located in the region above the one machine plate  13   a  are filling and sealing devices for the containers, while a transport device for the containers is located in the region above the machine plate  13   b.    
     The interior  11  is defined by the machine plate  13  on one side and by an insulator housing  15  sealingly surrounding the plate  13 . The hoodlike insulator housing  15  has side walls  16 , in which inspection windows  17  are inserted. Inserts  18  for rubber gloves, for instance, are also disposed in the inspection windows  17 , so that manipulation can be done by hand in the interior  11 . Locks, not shown, are also embodied on the face ends  19 ,  20  of the insulator housing  15 , so that the containers can be introduced into the interior  11  and shunted out of the housing. 
     To prevent unsterile air from entering the interior  11  through the aforementioned locks and to develop a well-aimed air course with as laminar an air flow as possible inside the interior  11 , a blower or recirculating system is used, which is disposed in a chestlike region  23  in the upper part of the insulator housing  15 . A recirculating fan, for instance, is located in this region  23  along with sterile air filters, which clean the air aspirated from the interior  11  and carry the air in a well-aimed way back into the interior in terms of their flow direction and flow speed. The aspiration of the air from the interior  11  preferably takes place in the peripheral regions of the insulator housing  15 , and the inspection windows  17  are therefore embodied as double-paned windows with inner panes  24 . The inner panes  24  extend to just above the machine plate  13 , so that the air is aspirated via the peripheral gaps  25 . 
     In order also to prevent unsterile air from reaching the interior  11  via the point of contact between the machine plate  13  and the insulator housing  15 , it is necessary for the insulator housing  15  to be sealed off from the machine plate  13 . With respect to the prior art, FIG. 3 will now be described in this respect: It can be seen here that the machine plate  13   c  comprises a solid base plate  26  and a sheet-metal cover plate  27  that covers the base plate  26 . The cover plate  27  has an edge  28  bent at an angle, and this edge laterally covers the circumference of the base plate  26 . A through bore  31  is formed in a region  29  of the base plate  26  that protrudes laterally past the machine stand  12 . A spacer sleeve  33  aligned with the through bore  31  is also disposed in an interstice  32  between the base plate  26  and the cover plate  27 . A threaded bolt  34  is disposed inside the spacer sleeve  33  and the through bore  31 , and the threaded bolt  34  penetrates the cover plate  27  in the region of a hole  36  and cooperates with a nut  35 . The threaded bolt  34  is fastened or welded to a sheet-metal profile frame  38 . The profile frame  38  is embodied as a closed frame or chest  39 , which receives the inspection windows  17  with the interposition of inflatable molded seals  40 . A curved wall  41  of the chest  39  extends in a straight line, on the side toward the machine plate  13 , in a peripheral zone  42 , which covers the cover plate  27  to approximately the height of the machine stand  12 , and the threaded bolt  34  is secured to its underside. A sealing element, for instance in the form of a sealing band  43 , is also disposed between the peripheral zone  42  and the cover plate  27 , and this sealing band is adjoined, on the side toward the interior  11 , by a silicone bead  44  serving as a termination. 
     A first coupling according to the invention of the insulator housing  15  to the machine stand  12  will now be is described in conjunction with FIG.  4 : The machine plate  13  used here, in contrast to the machine plate  13   c  of the prior art, protrudes laterally only somewhat past the machine stand  12 , and this is predominantly for reasons of appearance. A plurality of retainers  45  are disposed laterally on the machine stand  12 . These retainers  45  serve as a bearing face and capability of fastening the insulator housing  15  to a profile frame  46 . The profile frame  46  has a basic profile  47  of rectangular cross section, which with its short side  48  rests on the top side  49  of the carriers  45  and is fastened replaceably to the carriers  45  in some suitable way, for instance by means of screw connections  51 . The basic profile  47  is defined laterally at least in part by two molded metal sheets  53 ,  54 , which on the side remote from the carriers  45 , together with the molded seal  40  make it possible to receive the side wall  16  in a tight and positive way. The molded metal sheet  54  oriented toward the machine plate  13  has a curvature  55  which comes to an end at the level of the top of the cover plate  27 , as well as a bent portion  56  disposed at least substantially parallel to the edge  28  of the cover plate  27 . The spacing between the portion  56  and the edge  28  of the cover plate  27  is approximately 3-10 mm; the gap  57  thus formed has a length such that a sealing element  58  can be disposed in the gap  57 . In the first exemplary embodiment of the invention shown in FIG. 4, this sealing element  58  is in one piece, for example being embodied as a molded seal or as an inflatable sealing element  58 . 
     The second exemplary embodiment shown in FIG. 5 differs from the first exemplary embodiment of FIG. 4 in its sealing element  58   a , which now comprises two pieces: a sealing band  59 , and a silicone bead  60 . The sealing band  59  is located in the gap  57 , while the silicone bead  60  makes a smooth transition possible between the cover plate  27  and the molded metal sheet  55  toward the insulator housing  11 . 
     The third exemplary embodiment of the invention, shown in FIG. 6, differs from the first two exemplary embodiments of the invention in dispensing with an inner plate  24 , between which and the side wall  16  the aspiration of air otherwise takes place. In FIG. 6, the profile frame  61  is embodied as a chest of closed cross section, which on the side toward the interior  11  has an oblique boundary wall  62  with aspiration bores  63 . The profile frame  61 , or the aspiration conduit  64  formed by the profile frame, communicates with a negative-pressure source, not shown, which makes it possible to aspirate air out of the interior  11  through the aspiration bores  63 . 
     It will additionally be noted that the retainers  45  can also be installed even with machine stands  12  that are not coupled to an insulator housing  15 . In that case, the retainers  45  can serve as a means of securing a lining or the like. 
     The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.