Abstract:
The invention relates to a sealing bar for a vacuum drawer for vacuuming food, having a base support which comprises at least one welding wire extending in the longitudinal direction over the surface, with the welding wire being fastened to the base support by means of a clamping connection at one side or at both sides.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a sealing bar for a vacuum drawer for vacuuming food, having a base support which comprises at least one welding wire extending in the longitudinal direction over the surface. The invention further relates to a vacuum drawer having a corresponding sealing bar. 
         [0002]    Vacuuming units comprise a vacuum pump into which a suitable container, for example in the form of a sealable bag, is placed. A sealing bar which is vertically adjustable in the vertical direction extends within the chamber. The 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 bag is sealed due to the heat development by supplying the required welding energy. 
         [0003]    It must be ensured for the welding process that the welding wire is uniformly contacted since otherwise local overheating of the welding wire and corresponding damage may occur. Since a uniform contact may not be able to be ensured under certain circumstances on a heat-induced lengthening of the welding wire, a corresponding spring element was previously integrated to compensate the lengthening. 
       SUMMARY OF THE INVENTION 
       [0004]    The subject of the present invention deals with the object of providing an alternative fixing of the welding wire to the base support of the sealing bar. 
         [0005]    This object is achieved by the sealing bar 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, it is proposed with the sealing bar of the category having base support which comprises at least one welding wire extending in a longitudinal direction over the surface to fasten the welding wire to the base support with a preload such that the latter lies areally over its total length on the base support. Due to the preload it is ensured, that the heating wire has an areal contact everywhere and the heat can be dissipated. The heating wire would otherwise overheat at the position without heat dissipation. 
         [0007]    The heating wire is ideally fastened indirectly or directly to the base support at one side or at both sides via a clamping connection. The welding wire can be flexibly fastened to the base support with a certain preload due to the clamping connection of the welding wire to the base support, preferably by clipping the ends of the welding wire into corresponding clamps. The preload provides that uniform contact between the welding wire and the environment, i.e. the base support, is also ensured on a heat-induced lengthening of the welding wire. 
         [0008]    The welding wire is preferably led to the lower side via the transverse edges of the base support and is fixed thereto at the lower side by means of a clamping connection. The base support preferably comprises radii at the end sides about which the welding wire extends with areal contact. 
         [0009]    The fixing to the base body preferably takes place by means of clamping means; a respective separate clamping means is preferably provided per free end of the welding wire. The welding wire itself is fixed to the clamping means at the end side via a clamping connection. The fastening of the clamping means to the base body can basically take place in any desired manner; however, a releasable connection of the clamping means to the base support is preferred. 
         [0010]    In accordance with a preferred embodiment variant, the fastening of the one or more clamping means to the base support takes place via at least one hook of the clamping means. Said hook can be hung at the base support. The clamping means is preferably fixed below the surface of the base support and the hook is hung at the transverse edge of the surface of the base support. 
         [0011]    Provision can additionally be made that one or more latching hooks are provided at the base element below its surface which latch into corresponding cut-outs of the clamping means and thus allow a shape-matched connection between the base support and the clamping means. 
         [0012]    It is a particular advantage of the embodiment with the aid of the clamping means in this respect that the clamping means can be used to achieve a lever effect or a wedge effect. A sufficient preload of the clamped welding wire is achieved automatically by hooking in the clamping means and by attaching them to the lower side of the base support, preferably by a rotational movement with the hook connection as an axis of rotation. 
         [0013]    The clamping means preferably consist of an electrically conductive material or at least comprise an electrically conductive material, preferably a conductive metal. 
         [0014]    The clamping means in this case simultaneously serve as connection points for the electrical supply of the welding wire. A corresponding opening on the lower side of the clamping means is conceivable which can be plugged onto corresponding connection spigots on the installation of the sealing bar within a vacuum drawer. 
         [0015]    The clamping means advantageously comprise a groove for providing the clamping connection and the welding wire can be pressed into said groove by a pressing part of the clamping means. The pressing part itself can be arranged movably, in particular flexibly, at the clamping means. 
         [0016]    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 supported in the vacuum chamber. The advantages and properties of the vacuum drawer in accordance with the invention thus correspond to those of the sealing bar in accordance with the invention. A repetitive description is dispensed with for this reason. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Further advantages and properties of the invention will be explained below in detail with reference to an embodiment shown in the Figures. There are shown: 
           [0018]      FIGS. 1 a , 1 b   : two isometric representations of the vacuum drawer in accordance with the invention; 
           [0019]      FIG. 2 : a perspective view of the frame part of the sealing bar in accordance with the invention; 
           [0020]      FIG. 3 : the frame part of  FIG. 2  in an exploded representation; 
           [0021]      FIG. 4 : a sectional representation of the sealing bar in accordance with the invention transversely to its longitudinal axis; 
           [0022]      FIG. 5 a   : a sectional representation of the base support along the longitudinal axis; 
           [0023]      FIG. 5 b   : a detailed view of the representation in accordance with  FIG. 5 a   , and 
           [0024]      FIG. 6 : an exploded representation of the base support of the sealing bar. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    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. 
         [0026]    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. 
         [0027]    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. 
         [0028]    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 extends almost completely over the surface of the sealing bar  22  in its longitudinal direction. 
         [0029]    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. 
         [0030]    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 . 
         [0031]    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. 
         [0032]    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 . 
         [0033]    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. 
         [0034]    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 . 
         [0035]    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.    
         [0036]    The welding wire  42  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. 
         [0037]    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 . 
         [0038]    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 .