Abstract:
A medical appliance, in particular an apparatus for extracorporeal blood treatment, has a housing including a door and with a handle mechanism arranged at the door, via which the door can be locked with the housing via a locking mechanism. A part of the locking mechanism is formed at the handle mechanism in a part thereof that protrudes into the housing. A form-fit unit includes at least one form-fit element and at least one form-fit element counterpart, such that on locking and/or closing the door, the at least one form-fit element at least partly engages in the at least one form-fit element counterpart.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of allowed U.S. application Ser. No. 13/361,015, filed Jan. 30, 2012, now issued as U.S. Pat. No. 9,101,703, the disclosure of which is incorporated by reference as if fully set forth herein. The aforementioned U.S. application Ser. No. 13/361,015 claims benefit of U.S. Provisional Application 61/457,220. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates to a medical appliance, in particular an apparatus for the extracorporeal blood treatment, having a housing including a door, and with a handle mechanism arranged at the door, via which the door can be locked with the housing via a locking mechanism. 
     2. Description of the Prior Art 
     Medical appliances, such as apparatuses for the extracorporeal blood treatment, usually have a housing which for cost reasons very often is made of a simple sheet-metal construction. The housing might also be a supporting plastic construction. In particular, it is conceivable that the housing includes a supporting sheet metal construction which is framed with plastic parts. In the housing at least one door generally is provided, which leaves an inspection opening for the service technician. Usually, a corresponding handle for opening the door is arranged at the door. 
     Apparatuses for the extracorporeal blood treatment are known as so-called acute dialysis machines, which serve for use in intensive care units and for this purpose are designed to be movable on rollers. To move such acute dialysis machine with a weight of approximately 85 kg, the same usually is held by the door handle. 
     Thus, the door handle has a dual function. On the one hand, it serves the service technician for opening and closing the door and on the other hand it serves the user of the dialysis machine in the hospital as a handle for pushing the entire dialysis machine. While pushing the machine, forces are transmitted from the handle mechanism to the housing. 
     In some cases of use, the door constitutes the entire housing front and is provided with a circumferential elastic seal which on closing is pressed against the frame of the stationary housing. In doing so, the seal should not be pressed against the frame either too strongly or too weakly. In addition, manufacturing tolerances must be compensated, which are inevitable due to the use of the canted inexpensive sheet-metal construction. 
     Despite these manufacturing tolerances, the door on the one hand should circumferentially abut in a sealing manner without distortion and on the other hand the handle should not have a noticeable clearance on pushing the dialysis machine. When using known door handles, the seal is deformed in addition when pushing the dialysis machine. The fact that the handle noticeably yields while being pushed by the user provides the entire dialysis machine with a negative quality impression, which should be avoided. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is the object of the present invention to provide a medical appliance which includes a door handle which despite a simple construction should feel massive and should not yield on pushing the medical appliance. At the same time it should be possible to open and close the door of the medical appliance via the handle. 
     In accordance with the invention, this object is solved by a medical appliance having the features described herein. Accordingly, the medical appliance has a housing comprising a door and a handle mechanism arranged at the door, by means of which the door can be locked with the housing via a locking mechanism. At the handle mechanism a part of the locking mechanism is formed in its part protruding into the housing, which cooperates with the other part of the locking mechanism on the side of the housing. It is provided that at the handle mechanism, in its part protruding into the housing, a part of the locking mechanism is formed and that at least one form-fit unit is provided which includes at least one form-fit means and at least one form-fit means counterpart, wherein on locking and/or closing the door that at least one form-fit means at least partly engages in the at least one form-fit means counterpart. 
     This involves the advantage that a defined positioning of the door with respect to the housing can be achieved. In particular it is advantageous that correct closing thereby can be ensured in a safe and simple way, with a simple construction being possible at the same time. 
     The housing can be fabricated of a simple sheet-metal construction. The housing might also be a supporting plastic construction. Advantageously, it is conceivable in particular that the housing includes a supporting sheet metal construction which is framed with plastic parts. In an advantageous aspect, the medical appliance can be a dialysis machine, e.g. an acute dialysis machine. 
     Advantageous aspects of the invention are described in the following detailed description. 
     It can be provided that at least one form-fit means and/or at least one form-fit means counterpart is arranged at and/or integrally molded and/or attached to the handle mechanism. 
     It is furthermore conceivable that at least one form-fit means and/or at least one form-fit means counterpart is arranged and/or integrally molded and/or attached on the side of the housing. 
     In particular, it is advantageously possible that on the side of the housing and on the side of the handle mechanism both at least one form-fit means and at least one form-fit means counterpart are provided. Just as well it is, however, also possible that on the side of the housing the form-fit means is provided and on the side of the handle mechanism the form-fit means counterpart is provided. As a further equally advantageous possibility it is, however, also conceivable that on the side of the handle mechanism the form-fit means is provided and on the side of the housing the form-fit means counterpart is provided. 
     In addition, it can be provided that the at least one form-fit means and/or at least one form-fit means counterpart is elastically mounted. 
     It is furthermore possible that the form-fit unit includes a tapered spigot as form-fit means and a conical receptacle as form-fit means counterpart. 
     It is conceivable that on closing the handle mechanism engages in at least one tapered spigot elastically mounted on the side of the housing via at least one conical receptacle and/or that on closing the handle mechanism engages in at least one conical receptacle on the side of the housing via at least one tapered spigot elastically mounted on the side of the handle mechanism. On closing the door by means of the locking mechanism, the at least one conical receptacle thus advantageously is pretensioned into the at least one tapered spigot elastically mounted on the side of the housing and/or on the side of the handle mechanism such that on pushing the medical appliance the usual thrust forces received by the handle can be transmitted to the housing, without the handle being displaced with respect to the housing. At the same time, the at least one elastically mounted tapered spigot advantageously can compensate the manufacturing tolerances in all directions. 
     It is furthermore possible that at least one spring means is provided, by means of which the at least one form-fit means can be pretensioned. 
     Advantageously it can be provided that the spring means is and/or comprises a compression spring, a coil spring and/or a disk spring and/or that the spring means is at least partly formed by elastic regions of the housing. 
     It is in particular conceivable that the at least one tapered spigot is pretensioned via at least one disk spring. By using the disk springs, the tapered spigots advantageously can elastically be mounted on the housing, more exactly on the housing frame, in a three-dimensional way. 
     The disk springs can be pretensioned by a desired amount, in order to nevertheless provide for a sufficiently rigid transmission of force from the handle to the housing after closing the door and elastically compensating possible tolerances. 
     In accordance with a further preferred aspect of the invention a plurality of tapered spigots are arranged in the housing in at least two planes. Preferably, four tapered spigots are present here in two different planes of the housing frames. An alternative configuration can, however, also consist in that in one plane two tapered spigots are present and in a second plane a single tapered spigot is present. 
     The locking mechanism can include a pivotable hook which cooperates with a tension bolt in a known way for locking and unlocking the door. The pivotable hook can be provided with a latch in the usual way, by means of which the locking mechanism can be opened. 
     In accordance with one configuration variant the handle mechanism is firmly connected with the door. In another configuration variant the handle mechanism extends through the door in a longitudinally movable manner. In accordance with this configuration variant the handle mechanism includes at least one tension spring which can be tensioned on closing the door. 
     Due to the spring force of the at least one tension spring a defined compression of a seal arranged between the door and the housing, to be more exact the housing frame, is effected. In accordance with a further preferred aspect the pressing force is designed in dependence on the seal used. In so far, a uniform compression of the seal additionally is ensured by this configuration variant. 
     It is furthermore conceivable that at least a part of the housing front is formed as door. 
     In accordance with an advantageous configuration variant the entire housing front is formed as door. The door can be rotatably mounted about its lower edge, as is known for example from a baking oven door, whereas the handle mechanism is arranged on the opposite side of the door, i.e. close to the upper edge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, details and advantages of the invention will be explained in detail with reference to an embodiment illustrated in the drawing, in which: 
         FIG. 1 : shows a sectional representation through a part of the medical appliance in accordance with one configuration variant of the present invention, 
         FIG. 2 : shows a further sectional representation of the detail of  FIG. 1  in an open position, 
         FIG. 3 : shows the detail representation of the medical appliance of  FIG. 2  in a closed, but not yet locked position, 
         FIG. 4 : shows a perspective, partly sectional representation of the medical appliance corresponding to  FIG. 2  in an open position, 
         FIG. 5 : shows a representation according to  FIG. 4  in a closed position, and 
         FIG. 6 : shows a detail section through another part of the medical appliance. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     The Figures merely show the handle region or closure mechanism of a door  12  closing a housing of a non-illustrated medical appliance. The medical appliance advantageously, but not exclusively, can be an acute dialysis machine, which usually is mounted on rollers, so as to be able to move the same to the respective intensive care bed for use in an intensive care unit. 
     For this purpose, the entire device is seized by the handle  14 . The handle  14  includes a handle bar  16  which is attached to the free end of a handle web  18  protruding from the door  12 . The handle web  18  extends through the door  12  and is movably mounted in the same, as can be taken in particular from  FIG. 1 . In the handle web  18 , a tension bolt  20  is inserted at the free end protruding into the housing  10 , which is part of a locking means  22 . 
     This locking means  22  substantially includes a pivotable hook  24  which cooperates with the tension bolt  20  and secures the door after correspondingly locking the tension bolt  20 . The construction of the locking means  22  is of the conventional type and can be purchased as a toggle latch for a butt-joint lock. It provides for the hook  24  automatically snapping into the tension bolt on closing the door  12  and for a release of the tension bolt  20  by the hook  24  after correspondingly opening the door by a manipulation not shown here in detail. 
     Both the entire housing  10  and the door  12  are made of a canted sheet-metal construction. At the upper edge of the door  12  a circumferential seal  26  is provided, which is directed towards the housing  10 . 
     The seal should rather uniformly rest against the canted supporting edge or frame of the housing  10 . 
     To ensure a safe and completely closed contact of the seal  26  in the region between the door  12  and the housing  10 , the handle  14  movably mounted in the door  12  in direction of the double arrow A as shown in  FIG. 1  can be pretensioned via springs  28 . For closing the door  12 , the handle thus is pressed into the door against the spring force of the springs  28 , until the hook  24  secures the tension bolt  20 . The spring force of the springs  28  is chosen such that a rather uniform pressure is exerted on the door  12 , so that the seal  26  reliably rests on the circumferential edge of the housing  10  and performs its sealing function. 
     In the embodiment shown here, four tension springs  28  are provided. Thus, on closing the door the door  12  first meets with the circumferential frame of the housing  10 , while the handle  14  continues to move through the lead-through into its locking position and thereby tensions the tension springs  28 . The pressing force of the tension springs should be designed for the defined pressing of the door with the housing frame, each in dependence on the seal used. For a medium-soft seal a pressing force between 150 and 200 N can be chosen. In this way, relatively large manufacturing tolerances which are due to the fabrication of the sheet-metal parts can be compensated. 
     From  FIGS. 2, 3, 4 and 5  it can furthermore be taken that conical receptacles  30  are recessed at the handle web  18 . On closing the door  12 , the same cooperate with corresponding tapered spigots  32 . In the embodiment shown here, the form-fit unit comprises the conical receptacles  30  and the corresponding tapered spigots  32 . The form-fit means are formed by the tapered spigots  32  and the form-fit means counterparts are formed by the conical receptacles  30 . 
     With reference to  FIG. 6  the mode of action of the interlocking conical receptacles  30  and of the tapered spigot  32  can be explained. On its bottom surface the tapered spigot  32  includes a threaded bolt  38  via which it can be put through the frame  36  of the housing  10  and be fixed with a nut  40 . On the opposite side of the frame  36 , disk springs are pushed onto the threaded bolt  38 , which can be pretensioned via the nut  40 . As can furthermore be taken from  FIG. 6 , a sufficient radial clearance is present around the threaded bolt  38  in the bore extending through the frame  36 . Due to the pretensioned disk springs via which the threaded bolt  38  supports on the frame  36  of the housing  10  and the radial clearance in the region of the bore, a three-dimensional elastic bearing is ensured, as is indicated by the movement arrows in  FIG. 6 . 
     As can now be taken from  FIGS. 2, 3, 4 and 5 , corresponding tapered spigots  32  and conical receptacles  30  are provided at several points of the housing  10  and/or of the handle  14 . In this configuration variant two tapered spigots  32  are arranged in the set-back part of the housing, in which the hook  24  is rotatably mounted. As can clearly be seen in the Figures, the associated conical receptacles  30  are formed in the corresponding region of the handle web  18 , wherein in  FIGS. 2 and 4  the conical  30  do not yet sit on the tapered spigots  32 . In  FIGS. 3 and 5 , on the other hand, the conical receptacles  30  are already coupled with the tapered spigots  32  elastically mounted on the side of the housing. Two tapered spigots  32  also are coupled with further conical receptacles  30  arranged at the handle web  18 , which are arranged in the outer frame region of the housing  10  and hence are arranged in a different plane than the above-described tapered spigots  32 . 
     The spring rigidity of the disk springs  34  used in the tapered bolts is designed such that the usual thrust forces on pushing the medical appliance, i.e. in the present example the dialysis machine, cannot lead to noticeable elastic deformations of the disk springs. This results in the haptic feeling of a “massive” and rigid handle  14  and a direct force transmission of the thrust forces to the medical appliance. Furthermore, the three-dimensionally elastically mounted tapered spigots  32  compensate the manufacturing tolerances in all directions. Beside the four tapered spigots  32  illustrated in this configuration variant one embodiment might also consist of only three or two tapered spigots which are arranged on two planes. Correspondingly dimensioned, an embodiment with a single tapered spigot also can already provide the effect in accordance with the invention. 
     The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims.