Abstract:
The invention relates to a medical or dental-medical apparatus, having a delivery line for a liquid and having a screw bushing onto which a container for the liquid can be screwed, the delivery line extending from the interior of the container to the outside and penetrating the screw bushing, a compressed gas line penetrating the screw bushing from the outside inwardly, and the compressed gas line being closable and openable by means of a valve. In order to simplify the operating effort, the screw bushing is rotatably mounted in a rotary bearing and is in working connection with a switch cam which, in a rotary position of the screw bushing which is rotated in the screwing-on direction, opens the previously closed valve.

Description:
FIELD OF THE INVENTION 
     The invention relates to a medical or dental-medical apparatus of the type having a container for liquid, a delivery line for a liquid extending from the interior of the container through a screw bushing, and a compressed gas line extending into the gas container from the outside thereof through the screw bushing. 
     The invention relates to a medical or dental-medical apparatus in accordance with the preamble of claim  1 . 
     BACKGROUND OF THE INVENTION 
     When working with an apparatus of the kind concerned a liquid is needed which in functional operation is supplied through a delivery line to the treatment or working site. In the case of an apparatus for the treatment of the human or animal body there is needed a liquid which is safe from a health point of view. If a liquid of this quality, e.g. from the public water supply, is not available, it is known to take the liquid from a container, a so-called water bottle, associated with the treatment apparatus. For this purpose there serves a connection device for the container having a screw bushing into which the container is screwed from below with a threaded connection piece, for its connection. Before the screwing, an inlet end of the delivery line, projecting downwardly beyond the screw bushing is to be introduced into the opening of the container. Further, the apparatus has a compressed gas line which ends in the region of the screw bushing and in which a first valve for opening and closing the compressed gas line is arranged. After the screwing on of the container filed with liquid, the valve is manually opened so that the compressed gas enters into the container and can place the liquid located there under pressure, which flows out through the delivery line when a second valve arranged in the region of the delivery line is opened. For a dismounting or for an exchange of the container it is necessary to manually close the valve before screwing off the container. Upon screwing off of the container, the gas pressure still present in the container is released and a filled container can be mounted. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is so to configure a medical or dental-medical apparatus such that the operating effort is reduced. 
     This object is achieved by means of the features of claim  1 . Advantageous developments of the invention are indicated in the subclaims. 
     With the apparatus in accordance with the invention the screw bushing is rotatably mounted on a container carrier in a rotary bearing and it has a cam which in the rotary end position, directed in the screw-in direction, opens the previously closed valve. By these means, upon connection of the container, the valve is automatically opened and the container placed under pressure, so that the liquid located therein is ready, after an opening of the second valve, to flow out of the instrument. A special manual measure for opening the first valve is not necessary. The configuration in accordance with the invention thus makes possible a significant reduction of the operational effort. Furthermore, the risk is removed that it would be forgotten to open the first valve, which would lead to considerable disruption in a subsequent use of the apparatus. 
     It is further of advantage to so configure the first valve that upon its closure a venting of the container interior is made possible. By these means there is no escape of compressed gas upon screwing off and no noises arising therefrom. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Below, advantageous configurations of an exemplary embodiment in accordance with the invention will be described in more detail with reference to the drawings, which show: 
     FIG. 1 a medical or dental-medical apparatus in the form of a treatment chair having a connection device for a container, in a side view; 
     FIG. 2 the connection device, in a sectional illustration to an enlarged scale; 
     FIG. 3 the connection device, in a view from above; 
     FIG. 4 a schematic functional plan for a first valve in a gas pressure line, which shows the interior of the container in its working disposition connected with the connecting device; 
     FIG. 5 the connecting device in accordance with FIG. 2 in a modified consideration, and in a sectional illustration to an enlarged scale. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The main parts of the apparatus or treatment chair, designated as a whole with  1 , are a patient seat  2 , having a backrest and also a head support, which is in particular mounted height-adjustably on a chair base  3 . Next to the patient seat  2  there are arranged on a housing  4 , a cuspidor  5  with a rinsing arrangement and a water beaker  6  with a tap  7  for water. There is installed in the housing  4  a supply arrangement, designated overall with  8 . Further, one or more treatment instruments  9 , e.g. having a spray handpiece and a drill handpiece, are provided which are in each case connected with the supply arrangement  8  by means of a flexible supply line  11  and can be deposited at or on a repository device  12  which is preferably mounted horizontally pivotably, e.g. on the housing  4 . For switching on and switching off various functions of the apparatus  1 , e.g. drill drive or spray of a treatment liquid out of the treatment instrument  9 , there is provided a switch  10 , e.g. a foot switch. 
     In or on the housing  4  there is arranged at a readily accessible location a connection device  13  for a container  14  which constitutes a reservoir for the treatment liquid and after emptying through use during patient treatments is replaced by a full container  14 . 
     The container  14  has, in accordance with FIG. 2, at its upper end an approximately vertical threaded connecting piece  15  having an external thread  16   a  which is preferably a double-start thread. The connection device  13  has a screw-in bushing  17 , open downwardly, having an internal thread  16   b  into which the threaded connecting piece  15  can be so far screwed that a shoulder  18  on the container  14  closely bears on a shoulder  19  on the screw-in bushing  17 , e.g. with the intermediate mounting of a sealing ring  21 . With the present exemplary embodiment, the shoulder  18  is formed by means of the upper edge of the threaded connection piece  15  and the counter-shoulder  19  is formed by means of the floor of the screw-in recess of the screw-in bushing  17 . The screw-in bushing  17  has the form of an upturned pot with a peripheral wall  22 , a ceiling wall  23  and a flange  24  on the lower side, which with the peripheral wall  22  may be stabilized by means of reinforcement ribs  25 . 
     The screw-in bushing  17  is freely rotatably mounted in a rotary bearing  26 , which e.g. is formed by means of an approximately vertical bore  27  in a plate-like carrier part  28  into which bore the screw-in bushing  17  engages from above with the lower edge of its peripheral wall  22  and engages therebelow with a securing part  29  attached thereto. 
     From the lower side of the ceiling wall  23  there extends downwardly a delivery line section  31   a  in the form of a tube or flexible hose, which is so long that it extends as far as the floor region of the screwed-on container  14 , and which forms the beginning end of the delivery line  31  for the supply of liquid to the at least one treatment instrument  9 . The delivery line section  31   a  may be plugged on to or a screwed on to a connection piece  32  projecting downwardly from the ceiling wall  23 . From the connection piece  32  there extends a channel  33 , through the ceiling wall  23 , and a plug-in coupling  34 , arranged on the upper side of the ceiling wall  23 , having a cylindrical plug recess and a cylindrical plug pin inserted therein from above with play for movement, which plug pin is arranged in a plug coupling part  35  which extends straight or angled, which plug coupling part has at it end opposite to the plug pin a connection piece  35   a  which is connected with a connection line  36  in the form of a tube or a flexible hose, e.g. by being pushed thereon, which is connected at its other end with the treatment instrument  9  or extends to the treatment site at the patient and likewise forms the delivery line  31 . A longitudinal arresting of the plug pin in the plug recess can be formed by means of a securing disk  37  which is attached to the upper side of the screw-in bushing  17  and engages into a ring groove worked into the outer surface of the plug pin. The plug coupling ensures a free rotatability, in the sense of the rotary coupling, between the screw-in bushing  17  and the plug pin. Therefore, the screw-in bushing  17  can be rotated without the connection line  36  having to rotate therewith. This can thus be of a non-flexible pipeline. It may, however, also be flexible, e.g. be formed by a hose. 
     In similar manner, a pressure line  39  for a flowable pressure medium, in particular compressed air, may be connected with the screw-in bushing  17 . In order to avoid repetition, attention is therefore directed to the description of the connection of the connection line  36 . The pressure line  39  does not, however, need to extend as far as the floor region of the container  14 , since it needs merely to open out in the upper region of the interior of the container  14  in order to place the interior under over-pressure. A pressure channel, penetrating the ceiling wall  23  and standing in connection with the pressure line  39 , is present but hidden in FIG.  1  and therefore not illustrated. Therefore, also the pressure line  39  may be formed by means of a rigid pipeline section or a flexible hose. 
     In the pressure line  39  there is arranged a valve  41  which in its initial disposition is in the closed position and which can be opened by means of the displacement of its valve cam  42 . A pilot cam  43  on a cam arm  44 , which acts against the valve cam  44 , may be provided before the valve cam  42 . The valve cam  42  or the pilot cam  43  cooperate with a switching cam  44  arranged on the periphery of the screw-in bushing  17  in such a manner that in the rotary initial position of the screw-in bushing  17  in accordance with FIG. 3 the pilot cam  43  or the valve cam  42  are located in their released position, in which the pressure line  39  is closed. Upon screwing-in of the container  14  the screw-in bushing  17  is rotated in the direction of the arrow  45 , whereby the switch cam  44  displaces the valve  41  into its open position. Preferably, the valve  41  also has a venting channel  46  which in the closed position of the valve  41  connects the container interior with the surroundings, for the purpose of venting. The valve  41  may be formed by means of a 3/2-way valve, which is illustrated in FIG. 4 in its position closing the pressure line  39 , in which the venting channel  46  is open for venting the container interior and is preferably connected with a sound damper  47 . In FIG. 4, a pressure source for pressure gas, in particular for compressed air, is designated with  48 . The valve  41  may be arranged on the carrier part  28  next to the screw-in part  17  and e.g. be bolted on. As FIG. 2 clearly shows, the connecting device  13  may be covered over by means of a protective cap  49  placed on the carrier part  28 . The overpressure in the container  14  can, however, also escape through the thread engagement upon screwing loose, so that a venting channel  46  can be omitted. 
     The free rotatability of the screw-in bushing  17  is preferably so restricted by means of respective stops that it can be rotated solely between its initial rotary position and its final rotary position. For this purpose there may serve a curved longitudinal hole  51 , preferably in the flange  24 , through which a stop pin  52  extends and bounds the above-described movements thereof. The stop pin  52  may be arranged e.g. on the carrier part  28  and stand upwardly therefrom. Thereby, the stops are formed by means of the longitudinal hole ends  51   a ,  51   b.    
     Upon joining the container  14  to the connection device  13 , here the screw-in bushing  17 , there is needed a certain torque M 1 , which is necessitated on the one hand through the friction upon screwing and on the other hand through an axial pressure of the threaded connection piece  15  on the seal  21 . This torque M 1  can readily be applied by manually grasping the container  14 . In order to prevent that the screw-in bushing  17  rotates upon screwing on of the container  14  and actuates the valve  41 , for the purpose of pressure connection, before the threaded connection piece  15  is sealingly connected with the screw-in bushing  17 , the rotary bearing  26  is so formed that the screw-in bushing  17  is rotatable therein only with a torque M 2  which is greater than the above-mentioned torque M 1 . The torque M 2  is likewise dimensioned so great that it can be manually produced without problem. As a consequence, upon connection of a container  14 , the container  14  is initially sealingly connected with the screw-in bushing  17  and then by means of further manual turning the screw-in bushing  17  is turned out of its initial rotary position into its final rotary position, in which the valve  41  is actuated and the container  14  acted on with pressure. The action with pressure effects an increase of the connecting forces effective between the container  14  and the screw-in bushing  17 . Under pressure, the container  14  can be released by screwing off only with a torque M 3 , which likewise can be manually applied without problem, which is greater than the above-mentioned torque M 2 . 
     The torque M 2  can be attained e.g. by means of a stiffness in the rotary bearing  26  or by means of a brake, the braking force of which is preferably adjustable. With the exemplary embodiment according to FIG. 5, in which the same or similar parts are provided with the same reference signs, such a brake  50  is present and preferably integrated into the rotary bearing  26 . The brake  50  has a preferably annular brake element  50   a , which is arranged on a part of the rotary bearing  26 , here on the screw-in bushing  17 , preferably in an angular groove  50   b , e.g. in the flange  24 . The brake element  50   a  can be formed by means of a ring of elastic material, e.g. rubber or plastics. With the present exemplary embodiment, the axial cross-sectional dimension of the brake element  50   a  is dimensioned to be so great that in the functional position illustrated in FIG. 5 the brake element  50   a  is axially elastically compressed and thereby pressed against the other rotary bearing part with an elastic braking force. By these means, the torque M 2  is secured. In order to be able to adapt the torque M 2  to a particular value, it is advantageous to form the preferably axial biasing force, with which the friction parts concerned are biased against one another, adjustably. With the present exemplary embodiment this can be achieved in that the securing part  29 , e.g. an edge flange engaging below the edge of the bearing bore  27 , is axially adjustable and is fixable in the adjusted position, e.g. is screwable or adjustable with a screw thread. 
     Within the scope of the present invention, the connection device  13  is also then capable of functioning when the screw-in bushing  17  is freely rotatably mounted; that is, is formed without brake or stiffness. In such a case it is possible to hold the screw-in sleeve  17 , upon joining of the container  14 , manually in the initial rotary position. In such a case, however, a two-handed operation would be necessary, whilst with the presence of a brake or stiffness, one-hand operation is possible. 
     In order, in the absence of a brake or stiffness, to avoid that the screw-in bushing  17  remains in its rotary end position and does not turn back with the container  14 , which e.g. can be brought about by vibrations during functional operation of the apparatus  1 , it is advantageous to associate with the screw-in bushing  17  in its final rotary position a positioning device  55  which prevents an undesired return rotation. Preferably, the positioning device  55  is formed by means of an elastically effective latching device, the spring force of which is only so great that the latching is overcome upon screwing-in and screwing-out of the container  14  and the thereby occurring rotation of the screw-in bushing  17 . With the present exemplary embodiment, the positioning device is formed by means of a latch depression  55   a  on the switch cam  44  into which the valve cam  42  or pilot cam  43 , standing under spring pressure, latch and upon return rotation are self-actingly pressed out. The positioning device may also be present with a brake or stiffness as is the case with the exemplary embodiment according to FIG.  5 . 
     Below, an exchange of the container  14  will be described by way of example as follows. The container  14 , connected by means of the connection device  13 , is manually turned in the release direction, whereby due to the effective torque M 3  the screw-in sleeve  17  is also rotated from the final rotary position to the initial rotary position. 
     Thereby, the switch cam  44  releases the valve cam, whereby the valve  41  self-actingly closes the pressure line  39  due to the valve spring present. In this rotary position, the screw-in bushing  17  is limited in its rotary movement by means of the pin  52  forming a stop. The rotary angle W of this rotary movement is less than 360°. An angle of 180 or 90° is more advantageous in order to reduce the effort for rotation. With the configuration in accordance with the invention, the rotary angle W is less than 90°, in particular only about 45°. Already in this rotary position, in which the thread engagement has not yet been turned, the interior of the container  14  is vented through the venting line  46  of the valve  41 . 
     With further screwing loose of the container  14 , the thread engagement is released through screwing out and a new container  14 , filled with treatment liquid, can be screwed in. Upon screwing in, after screwing fast, the screw-in bushing  17  is rotated into the opposite stop position, namely into the final rotary position, whereby the switch cam  44  opens the valve  41  and the pressure in the pressure line  39  can enter the container interior, so that this is ready for a release of the treatment liquid. By means of an opening of a non-illustrated second valve in the delivery line  31 , which in each case extends through the flexible supply line  11 , the issue of the treatment liquid can be controlled from the treatment instrument  9 , e.g. by means of a foot switch  10 , which the operating or treating person actuates. 
     In order to protect the delivery line  31  from contamination, it is advantageous to arrange a sieve or filter  58  therein, which serves to sieve or filter the liquid flowing into the delivery line  31  out of the container interior under the effect of pressure. With the present exemplary embodiment, a sieve or filter  58  is arranged at the inlet end of the delivery line  31  or of the hose  31   a . Preferably, a sleeve-like bushing  59  is provided which can be inserted in a clamping manner into or onto the delivery line  31  with a tapered pin  59   a , and has a bushing  59   b , enlarged in section, in which the sieve or filter  58  is fixedly placed. By these means there is formed a cartridge which can be economically manufactured and can be mounted, which as a prefabricated component and exchangeable part can be readily and rapidly mounted or dismounted.