Abstract:
The invention relates to a sealing bar for a vacuum drawer for the vacuuming of food, having a base support comprising at least one heating wire as well as having a frame part with an integrated non-stick coating, wherein the frame part is releasably fastenable to the base support.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a sealing bar for a vacuum drawer for vacuuming food as well as to a vacuum drawer which comprises a vacuum chamber having such a sealing bar. 
         [0002]    Vacuuming units comprise a vacuum chamber into which a suitable container, for example in the form of a sealable bag, is placed. An elongate sealing bar extends within the chamber and is installed transversely to the vacuum chamber. The sealing bar is vertically adjustable in the vertical direction. A container filled with food is placed into the vacuum chamber, the latter subsequently being closed in an airtight manner via a cover to generate a chamber vacuum by means of a vacuum pump. Since the sealing bar is first positioned in an open position, the air can also be sucked out of the container. The sealing bar is subsequently vertically adjusted and the bag is clamped between the sealing bar and the counterpart. The required welding energy is supplied to the integrated welding wire or to the welding wire of the sealing bar such that the bag, which frequently contains plastic, is sealed in an airtight manner due to the heat development. 
         [0003]    A heat-conductive non-stick coating is typically applied to the upper side of the sealing bar onto which the bag to be welded is placed and said non-stick coating transfers the heat development of the welding wire disposed thereunder to the bag lying directly on the coating. The coating is typically a suitable film which is adhesively bonded to the surface of the single-part sealing bar construction. The constant heat development during the welding process sooner or later produces visual wear phenomena of the non-stick tape, which is characterized by disturbing discoloration. The non-stick function and heat-conductive function of the tape can thereby also be impaired in addition to the visual deficiencies. The non-stick coating should be renewed from time to time for this purpose. An exchange of single films is practically impossible due to the adhesive bond so that the total sealing bar is replaced for reasons of simplicity. The high repair costs caused by the complete replacement are, however, undesirable. 
       SUMMARY OF THE INVENTION 
       [0004]    It is consequently the object of the present invention to provide a new construction of the sealing bar which allows a more favorable replacement of the non-stick coating. 
         [0005]    This object is achieved by a sealing bar for a vacuum drawer for vacuuming food in accordance with the features herein. Advantageous embodiments of the sealing bar are the subject of the description herein. 
         [0006]    In accordance with the invention, the innovative sealing bar comprises a base support which comprises the required welding wire as well as a frame part having an integrated non-stick coating, with the frame part and the base support being releasable connectable to or connected to one another. The sealing bar is accordingly configured in two parts so that it does not have to completely replaced, but only the frame part, including the coating, has to be exchanged to renew the nonstick coating. To replace the frame part, the complete sealing bar is removed from the vacuum drawer and the frame part is released from the base support for the replacement. The base support is ideally releasably latched to the frame part. The replacement is thus not only simpler, but also likewise less expensive. The coating can preferably be implemented by a non-stick tape which can also be replaced separately with a releasable fastening to the frame part. The repair costs thereby fall further. 
         [0007]    The non-stock coating is also thermally conductive in addition to the non-stick property and it in particular consists of thermally conductive material. The non-stick tape is a Teflon tape in accordance with a preferred embodiment. The non-stick tape preferably extends in parallel with the welding wire, i.e. the welding wire is covered by the non-stick tape to prevent a direct contact between the welding wire and the bag to be sealed. The non-stick tape easily transfers the heating development of the welding wire to the bag to be sealed, but due to the material composition of the non-stick tape, a sticking of the bag to the sealing bar is prevented. 
         [0008]    The frame part for receiving the non-stick tape can preferably have an opening at its upper side which is continuous in the longitudinal direction and which is covered at least partly, ideally almost completely, by the non-stick tape. The upper side of the frame part corresponds to the surface of the sealing bar onto which the bag is placed for sealing. 
         [0009]    The non-stick tape is preferably wider than the opening of the frame part. In this case, the longitudinal edges of the non-stick tape are bent or folded downwardly and project into the opening of the frame part into the interior of the sealing bar. The non-stick tape can be fixed in the interior of the sealing bar by means of the folded longitudinal edges. 
         [0010]    A dirt-collecting edge, which results in a visual deficiency on a corresponding contamination, may be produced between the opening edge and the non-stick tape under certain circumstances. At least one opening edge of the frame part, at least a longitudinal edge of the opening, is provided with a sealing lip to avoid the dirt-collecting edge. A “flowing” transition is provided between the frame part and the non-stick tape by the sealing lip, whereby the step between the frame part and the non-stick tape is considerably reduced. A reduced generation of dirt is produced at the transition. 
         [0011]    It is particularly preferred if the fold of the longitudinal edges of the non-stick tape forms a bent, step-like section which lies on the shape of the sealing lip with an exact fit or which extends at least partly around the sealing lip. 
         [0012]    The non-stick tape is preferably fixed to the frame part and/or to the base support. The connection can be releasable, for example by means of a clamping between the base support and the frame part, or it can be fixed by adhesive bonding. The adhesive bonding with the frame part is applied at least at points. A combination of a clamping connection and of an adhesively bonding connection is also conceivable. 
         [0013]    In addition to the sealing bar in accordance with the invention, the present invention additionally relates to a vacuum drawer, in particular for installation into a piece of furniture, having a vacuum chamber and at least one sealing bar in accordance with the present invention or in accordance with an advantageous embodiment of the invention, the sealing bar supported in the vacuum chamber. The same advantages and properties thus result for the vacuum drawer such as have already been explained in more detail with reference to the sealing bar in accordance with the invention. A repeat description is consequently dispensed with. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Further advantages and particulars of the invention will be explained in more detail with reference to the embodiment shown in the Figures. There are shown: 
           [0015]      FIGS. 1 a , 1 b   : two isometric representations of the vacuum drawer in accordance with the invention; 
           [0016]      FIG. 2 : a perspective view of the frame part of the sealing bar in accordance with the invention; 
           [0017]      FIG. 3 : the frame part of  FIG. 2  in an exploded representation; 
           [0018]      FIG. 4 : a sectional representation of the sealing bar in accordance with the invention transversely to its longitudinal axis; 
           [0019]      FIG. 5 a   : a sectional representation of the base support along the longitudinal axis; 
           [0020]      FIG. 5 b   : a detailed view of the representation in accordance with  FIG. 5 a   , and 
           [0021]      FIG. 6 : an exploded representation of the base support of the sealing bar. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    The two  FIGS. 1 a , 1 b    show isometric representations of the vacuum drawer in accordance with the invention. The representation of  FIG. 1 a    shows the pulled out drawer for regular vacuuming operation. The drawer has been pulled out a little further again for maintenance purposes in  FIG. 1 b    to allow a view of the vacuum pump  30 . The drawer is suitable for use in a piece of kitchen furniture since it is characterized by an installation height of approximately 140 mm and accordingly corresponds to the standard dimension of fitted kitchens. 
         [0023]    The vacuum drawer comprises a drawer extension  10  which is longitudinally displaceably guided over lateral guide rails in a drawer carcass  12 . In the embodiment shown, the front cover  11  is handle-less and the drawer extension is designed as a push-pull device for opening and closing. A vacuum chamber  20  is supported within the drawer extension and is coupled fluidically to a vacuum pump  30  of the vacuum drawer to pump the air out of the closed vacuum chamber  20 . The vacuum chamber  20  can be closed in an airtight manner via the cover  21  pivotably mounted to the chamber  20 . The cover  21  itself can be produced from glass for design reasons. 
         [0024]    A sealing bar  22 , which extends in the chamber interior in the extension direction of the drawer, serves for the sealing of an inserted bag. A bag filled with food is placed into the chamber  20  for vacuuming and the cover  21  is closed in an airtight manner. The bag can be sealed by means of the sealing bar  22  after the evacuation of the chamber  20  by means of the vacuum pump  30  visible in  FIG. 1 b   . The bag opening to be sealed is then placed onto the sealing bar  22  which presses the bag against a contact point after the vacuuming and seals it by the effect of heat. The bar  22  can be pressed either to a counter-pressing bar  23  fastened to the cover  21  or against an alternative pressing surface. The vacuum pump  30  is seated behind the chamber  20  at the rear part of the drawer extension  10  and is coupled fluidically to the vacuum chamber  20  to pump the air out of the chamber  20  to generate the vacuum. 
         [0025]    The sealing bar  22  comprises a base body  40  as well as a frame part  25  which is equipped with a Teflon tape  26 . On the sealing procedure, the sealing bar  22  contacts the inserted bag via the Teflon tape  26  and the heat produced by the welding wire  42  is output to the bag via the Teflon tape  26 .  FIG. 2  shows a perspective representation of the frame part  25  for the sealing bar  22  in accordance with the invention. The frame part  25  comprises the Teflon tape  26  which also extends almost completely over the surface of the sealing bar  22  in its longitudinal direction. 
         [0026]    The two-part design of the sealing bar  22  comprising the base body  40  and the frame part  25  allows a fast, simple and inexpensive replacement of the Teflon tape  26 . Either the total frame part  25  or only the Teflon tape  26  can be replaced. 
         [0027]    The exploded representation of  FIG. 3  shows the complete Teflon tape  26  as well as the nature of the surface of the frame part  25 . The frame part  25  comprises a cut-out  28  on its surface  27  onto which a bag to be correspondingly sealed is placed during the sealing process. The longitudinal edges  29  of the Teflon tape  26  are folded downwardly and the resulting width of the Teflon tape  26  thus approximately corresponds to the opening width of the cut-out  28 . The Teflon tape  26  can thereby be inserted into the opening  28  and an almost stepless surface  27  of the frame  25  is produced with an extremely small offset at the transition between the frame part  25  and the Teflon tape  26 . 
         [0028]    The folding edge  31  of the Teflon tape  26  is, however, not a simple edge, but the fold rather forms a curved, step-like section  31 . The exact extent of the section can be seen from the cross-sectional representation of  FIG. 4 . Due to the selected section shape  31 , the Teflon tape  26  can lie tightly at the two sealing lips  32  of the frame part  25  which each extend along the longitudinal edges of the opening  28 . The sealing lips  32  reduce the offset in the transition between the frame part  25  and the Teflon tape  26  such that the risk of contamination at the transition is minimized. 
         [0029]    It can furthermore be seen from  FIG. 4  that the frame part  25  is placed on the base support  40  of the sealing bar  22  from above. An inner wall  33  projects inwardly or downwardly into the sealing bar  22  in the region of the opening edges of the opening  28  of the frame part  25 , whereby an opening wall is formed. This inner wall  33  extends in parallel with the oppositely disposed side wall  41  of the base support  40 . The inner wall  33  moreover extends in parallel with the respective outer wall  34  of the frame part  25 . There is a gap between the inner wall  33  and the outer wall  34 . 
         [0030]    The welding wire  42  extends in the longitudinal direction on the surface  45  of the base support  40 . If the frame part  25  is placed onto the base support  40  from above, the welding wire  42  is disposed directly below the Teflon tape  26 , whereby an ideal heat transfer is produced. The Teflon tape  26  can be fixed to the sealing bar  22  by a clamp connection. For this purpose, the folded longitudinal edges  29  are clamped between the side wall  41  of the base support  40  and the inner wall  33  of the frame part  25 . A sealing clamping likewise takes place with the surface of the base support  40  in the region of the sealing lips  32 . The Teflon tape  26  can moreover additionally be adhesively bonded to the frame part  25  or can be fastened thereto in a different manner. 
         [0031]    On the placing of the frame part  25  onto the base support  40 , the lower edge of the inner wall  33  is clipped at the end side into the groove  44  of the base support  40  formed by the projection  43 . 
         [0032]    The fastening of the welding wire  42  to the base support  40  will be explained in more detail in the following with reference to  FIGS. 5 a , 5 b    and  6 .  FIG. 6  shows an exploded representation of the base support  40 , while  FIG. 5 a    shows a longitudinal section through the base support  40 .  FIG. 5 b    represents a detailed section of the right hand side of the base support  40  of  FIG. 5   a.    
         [0033]    The welding wire  40  is clamped in the longitudinal direction over the total surface  45  of the base support  40 , with the free welding wire ends being guided over the end edges of the base support  40  at its lower side. The fixing of the welding wire  42  to the base support  40  is achieved using clamping means  50 . They are produced from an electrically conductive material and simultaneously represent the connection points of the sealing bar  22  for the electric supply. 
         [0034]    A hook  51 , which is formed by the rounded end edge  56  of the clamping means  50 , is located at the upper side of the clamping means  50 . A groove  53  as well as a plug  52  which is flexibly fastened to the clamping means and which can be pressed into the groove  53  with an exact fit is located at the lower side of the clamping means  50 . A cut-out  55  is located at the upper side of the clamping means  50  and a further cut-out  54  is present at the rear side of the clamping means  50 . The free ends of the welding wire  42  are placed downwardly from the upper side over the groove  53  via a respective rounded end side  56  of the clamping means  50  and are clampingly fixed to the clamping means  50  by pressing the plug  52  into the groove  53 . 
         [0035]    The two clamping means can subsequently be hung at the base support  40  at the end side via the hooks  51 . The hooks are preferably hung in at the base support from above and are subsequently pressed below the lower side of the base support by an inward rotational movement. A sufficient tension of the welding wire is thus achieved by the lever effect associated therewith so that said welding wire extends uniformly and in a planar manner over the upper side  45  of the base support  40 . The preload is selected such that a uniform contact also takes place with a heat-induced lengthening of the welding wire  42 . In this position, the clamping means  50  are additionally latched via the cut-outs  54 ,  55  to the corresponding latching hooks  47 ,  48  of the base support  40 . It must also be mentioned that the clamping means  50  are located in a protected manner in the fixed position in a hollow space of the clamping bodies  50 .