Abstract:
A discharging device for dispensing liquids having a housing, control electronics, a liquid storage receptacle, a discharge orifice, a conveying device actuable manually by a first actuator which transports the liquid to the discharge orifice from the storage receptacle and a blocking device, which in a blocked state blocks the actuation of the conveying device and in a released state allows actuation of the conveying device. The blocking device includes an interlock device movable relative to the housing between first and second positions and a movement of the interlock device from the first to the second position causes the blocking device to assume the released state. The interlock device is biased by a spring device in the direction of the second position and a first retaining device is provided which retains the interlock device in the first position and which is releasable by a signal from the control electronics.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The invention relates to a discharging device for dispensing liquids, more particularly for dispensing pharmaceutical liquids, which discharging device includes a housing, control electronics, a liquid storage receptacle for storing the liquid prior to discharge thereof, a discharge orifice, a conveying device which can be operated manually by means of a first actuator and by means of which the liquid can be conveyed from the liquid storage receptacle to the discharge orifice for the purpose of dispensing the same, and a blocking device that can assume a blocked state, in which operation of the conveying device is mechanically blocked, and a released state, in which operation of the conveying device is possible, for the purpose of preventing another discharging operation from taking place during a blocking period following a discharging operation. For this purpose, the blocking device of a generic discharging device includes an interlock device that is capable of being moved relative to the housing between a first and a second position, the blocking device being configured such that a movement of the interlock device from its first position to its second position causes the blocking device to assume the released state. The interlock device is spring biased by a spring device in the direction of its second position. Furthermore, there is provided a first retaining device, by means of which the interlock device can be retained against the force of this spring device in its first position and which can be released by an electrical signal generated by the control electronics. 
     A generic discharging device is disclosed in DE 10 2008 064 559 A1. Provision is made in this device for the mechanical work involved in moving the blocking device between the blocked state and the released state to be imparted to the system by the user during the actuation of the device for the purpose of carrying out a discharging operation. Following the discharging operation, this mechanical work is stored in one or more spring devices held in the tensioned state by a retaining device. This retaining device is formed by a permanent magnet and an electromagnet in the embodiments disclosed in DE 10 2008 064 559 A1, the permanent magnet performing the actual retaining function, whilst it is rendered temporarily ineffective by means of the electromagnet for the purpose of transferring the blocking device to the released state, which is thus achieved. Thus the retaining device is released by activation of the electromagnet. 
     The interlock device of a generic discharging device need not directly serve for blocking the conveying device. Thus both the push rod 78 and the bolt 142 described in DE 10 2008 064 559 A1 are interlock devices in terms of the present invention, since the displacement thereof directly or indirectly results in achieving the released state of the blocking device. 
     The design of the retaining device as a permanent magnet and an electromagnet constitutes a very advantageous solution, but it also involves the problem that strong impacts, caused accidentally or willfully, may cause unwanted movement of the blocking device so as to achieve the released state before the blocking period has elapsed. This poses the risk of administration of an overdose of the active ingredient stored in the liquid storage receptacle. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to improve a generic discharging device to safeguard it from administration of an overdose. 
     According to the invention, this is achieved by the provision of a second retaining device for this purpose, by means of which the interlock device can be retained in the first position against the force of the spring device and which can be released by manual operation. 
     Thus, in addition to the first retaining device that can be released by the control electronics, the discharging device of the invention includes a second retaining device, which is operated by the user of the discharging device in accordance with its intended use. For example, a second actuator can be provided on the discharging device for this purpose. Due to the fact that the second retaining device is released manually, it can be configured to be more robust than the first retaining device in such a way that an impact on the discharging device does not result in displacement of the interlock device. More particularly, the second retaining device can hold the interlock device positively in its first position, for example by means of an additional retaining element that impedes the movement of the interlock device from its first position to its second position as long as there is no manual operation of the second retaining device by the user. 
     In order to move the interlock device to its second position, both retaining devices must be released—the first retaining device by means of the electrical signal and the second retaining device by means of manual control by the user. 
     Preferably, a discharging device of the invention comprises a first retaining device comprising a permanent magnet that is disposed and configured such that it can hold the interlock device in its first position. This embodiment comprising a permanent magnet has proved to be very advantageous, since the transfer of the interlock device to its first position itself results in establishment of the retained state without requiring the first retaining device to have additional mechanically displaceable components. Likewise, it is regarded as being advantageous when the first retaining device comprises an electromagnet, which, when powered sufficiently by the control electronics, results in the application of force to the interlock device, which applied force overcomes a retention force of the permanent magnet and thus causes the first retaining device to be released. 
     It is also advantageous when a sensor connected to the control electronics is provided for detecting the release of the second retaining device, the control electronics being configured to release the first retaining device in response to detection of the release of the second retaining device, provided that the blocking period has elapsed. 
     In this development, the first retaining device is thus not released permanently after the expiry of the blocking period, for example, by permanent application of power to the electromagnet, since this might involve high energy consumption depending on the configuration of the first retaining device. Instead, when the blocking period has expired, the control electronics assume a state in which they also release the first retaining device on detecting the manually triggered release of the second retaining device. The relevant sensor can be mounted on an actuator for the second retaining device or on the aforementioned retaining element provided for the purpose of preventing displacement of the interlock device to its second position. 
     Since it is not readily apparent to a user as to whether the blocking period has elapsed or not in such an embodiment in which the first retaining device is not released permanently following the expiry of the blocking period, it is regarded as being advantageous when a display device connected to the control electronics is provided, the control electronics being configured to indicate the expiry of the blocking period by way of the display device. The display device can be configured to provide acoustic and/or visual signals. It is preferable to use a liquid crystal display or a comparable display on which an appropriate symbol, for example a padlock, appears and then disappears on expiry of the blocking period. It is very preferable for three different symbols to be provided on the display so as to make it possible to distinguish between the three states of the discharging device, namely “locked, not releasable”, “locked, releasable”, and “unlocked, ready for use”. This can be achieved, for example, by a symbol on the display that turns on, blinks, or turns off depending on the state of the discharging device. Thus the user can recognize the current state of the discharging device by viewing the display. More particularly, any malfunction of the device preventing a changeover between two states can be readily detected. 
     Preferably, the second retaining device includes a retaining element which is capable of being moved relative to the housing by means of a second actuator and which assumes a retaining position for the purpose of mechanically preventing any movement of the interlock device, and which can be moved from this retaining position by means of the second actuator. 
     In a particularly simple embodiment, the actuator and the retaining element are in the form of a single component that is mounted on the housing so as to carry out a translatory or pivotal movement. Preferably, the retaining element is biased by a spring in the retaining position so that it automatically re-assumes the retaining position when the second retaining device has been manually released. 
     In a particularly advantageous embodiment, there is further provided a damping device that retards the movement between the retaining element and the housing. As a result, not even a very severe shock will be able to simultaneously result in a release of the first retaining device and of the second retaining device, since the damping device impedes rapid displacement of the retaining element. Preferably, the damping device can be provided in the form of a resiliently deformable component, for example, a foamed element that is deformed during the movement of the retaining element. The energy required for displacing the retaining element can be easily introduced by means of the second actuator, whereas a temporary shock to the discharging device, for example, when the latter is dropped onto the floor, is not sufficient to cause displacement of the retaining element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional aspects and advantages of the invention are revealed in the claims and in the following description of a preferred exemplary embodiment of the invention that is explained with reference to the drawings, in which: 
         FIG. 1  is an overall view of the discharging device of the invention, in which the external housing is removed, and 
         FIG. 2   a  to  FIG. 5   b  each constitute two illustrations of an application cycle of the discharging device shown in  FIG. 1 , starting from a blocked state of the device to the production of the released state to the restoration of the blocked state upon completion of the discharging operation. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a discharging device of the invention, in which an external part of a housing  9  is removed for the purpose of illustrating the construction of the device. 
     The discharging device has a liquid storage receptacle  10  and an applicator  12  including a nasal tube  14 . The applicator  12  is adapted to be depressed relatively to the liquid storage receptacle  10  in the direction of the arrow  2  by means of an actuator  12   a , in order to actuate an internal conveying device (not shown) in the form of a piston pump. During the course of such actuation of the conveying device, a pharmaceutical liquid, for example an analgesic, is drawn from the liquid storage receptacle  10  and delivered to a discharge orifice  16  located at the distal end of the nasal tube  14 , where it is dispensed in the form of a spray jet. 
     For the purpose of temporarily preventing a discharging operation, a blocking ring  20  is provided, which is mounted for rotation about an axis  3  oriented in the direction of actuation  2  and which, depending on its angular position, prevents the applicator  12  from being depressed by means of locating surfaces (not shown in the drawing). On the blocking ring  20 , a tab  22  is provided pointing outwardly in the radial direction for displacement, as described below in more detail, for the purpose of rotating the blocking ring  20 . 
     The discharging device is closed at the front by control electronics  18  comprising a liquid crystal display  19  for indicating status information. 
     These control electronics are configured to move the blocking ring  20 , at the end of a blocking period during which no discharging operation may take place, in the direction of the arrow  4   a  by means of the tab  22  into its released position or to initiate this movement of the blocking ring  20 . When the blocking ring is in this released position, a discharging operation can be effected by depressing the applicator  12 , as mentioned above. When this discharging operation has been carried out, the blocking ring  20  returns automatically in the direction of the arrow  4   b , and a new blocking period is started. The released state of the discharging device is restored by the control electronics  18  only after the blocking period has elapsed. 
       FIGS. 2   a  to  5   b  show the components for maintaining the blocked state and illustrate the cooperation thereof. For this purpose,  FIGS. 2   a  to  5   b  each show, on the one hand, the discharging device in its entirety with the control electronics  18  removed, and a separate illustration of the components of a blocking device  30  of the discharging device, as are essential to the invention, on the other hand. 
     The essential components are explained below with reference to  FIGS. 2   a  and  2   b . The tab  22  located on the blocking ring  20 , mentioned above, is guided by a slide  32  which is capable of being moved linearly in the direction of the arrow  6  and which is biased by a spring  34  in the direction  6   a  in which it must be moved for the purpose of producing the released state of the discharging device. The movement of the slide  32  in the direction  6   a  is temporarily prevented by means of an interlock device  40  and the retaining extension  40   d  thereof. This interlock device  40  is hingedly mounted on the housing so as to be pivotal about an axis  7  and is torque-biased by a spring  42  in the counterclockwise direction with reference to the view shown in the drawings. The fact that this torque bias applied by the spring  42  does not immediately cause pivoting of the interlock device  40  in the counterclockwise direction and thus a release of the slide  32  and its displacement in the direction  6   a  is due to the presence of two retaining devices  50 ,  60  adapted to prevent the interlock device  40  from pivoting. 
     The first retaining device  50  is formed by a permanent magnet  52 , for which a main section  40   a  of the interlock device  40  represents a pivotal anchor. Retained by the force of this permanent magnet, the free end  40   b  of the interlock device  40  therefore bears against a contact surface  54  of the permanent magnet  52  in the blocked state of the blocking device  30 , which contact surface  54  is stationary relative to the housing  9 . In the neutral state, the magnetic force of the permanent magnet  52  of the first retaining device  50  is alone sufficient to prevent the interlock device  40  from pivoting in the counterclockwise direction from the position shown in  FIGS. 2   a  and  2   b.    
     However, a second retaining device  60  is provided, since the magnetic retention force might be overcome if the discharging device should receive a sharp blow, for example when the discharging device is dropped. This second retaining device  60  comprises a retaining element  62  which can pivot about a pivot axis  8  and comprises a retaining member  64  that likewise prevents the interlock device  40  from pivoting in the counterclockwise direction by means of a contact surface  64   a . This retaining element  62  is torque biased by a spring  66  in the clockwise direction and is therefore securely retained in its retaining position shown in  FIGS. 2   a  and  2   b . The retaining element  62  is connected for co-rotation to a second actuator or button  70  that is accessible from the outside through a recess of the housing, as shown in  FIG. 1 . It is possible by means of this actuator  70  to pivot the retaining element  62  and thus also the retaining member  64  and the contact surface  64   a  against the force of the spring  66  in the counterclockwise direction. 
     As mentioned above,  FIGS. 2   a  and  2   b  illustrate the blocked state of the blocking device  30 . In this blocked state, the interlock device  40  is held in position against the force of the spring  42  by both the first retaining device  50  and the second retaining device  60  so that it prevents, by means of the retaining extension  40   d , any displacement of the slide  32  in the direction  6   a  and thus any movement of the blocking device  30  to attain the released state. 
     Isolated manual actuation of the actuator  70  in this state does cause pivoting of the retaining member  64  in the counterclockwise direction, as shown in  FIGS. 3   a  and  3   b . This only releases the second retaining device  60 , while the first retaining device  50  holds the interlock device  40  unchanged in its first position on account of the permanent magnet  52  and thus prevents the discharging device from assuming the released state. However, the actuation of the actuator  70  is detected by means of a sensor  72  and is transmitted to the control electronics  18 . During the blocking period, this detection does not cause the control electronics to exert any influence on the first retaining device  50 . 
     As soon as a blocking period, during which no discharging operation is possible in accordance with the designated use of the discharging device, has elapsed, this is indicated on the LC display  19  in that a symbol  19   a  previously displayed in a steady form assumes a blinking state. The user thus learns that the discharging device has entered a still locked but releasable state from a locked and non-releasable state. When the retaining element  62  comprising the retaining member  64  is pivoted by means of the actuator  70  following the thus indicated termination of the blocking period, as shown in  FIGS. 3   a  and  3   b , this is detected by the sensor  72 , and the first retaining device  50  is released by the control electronics  18  in addition to the second retaining device due to the fact that the blocking period has elapsed. An electromagnet  56  is energized for this purpose. This electromagnet  56  compensates for the retention force of the permanent magnet  52  so that as a result the torque of the spring  42  suffices to pivot the interlock device  40  about the axis  7  in the direction of the arrow  7   a.    
       FIGS. 4   a  and  4   b  illustrate this pivoting of the interlock device  40  together with the retaining extension  40   d . As a result of such pivoting, the slide  32  driven by the spring  34  is displaced in the direction of the arrow  6   a , and thus the blocking ring  20  is pivoted about the axis  3  in such a way that it no longer prevents the applicator  12  from being depressed. An unlocked state of the discharging device is thus established. This unlocked state is represented on the display  19  in that the symbol  19   a  no longer blinks, but is instead displayed in a steady state. As long as the discharging device is in the unlocked state shown in  FIGS. 4   a  and  4   b , it is thus possible for the user to actuate the conveying device (not shown) by depressing the applicator  12  and thus dispensing the pharmaceutical liquid through the discharge orifice  16 . 
     When the applicator  12  is depressed during this discharging operation and/or during the subsequent return stroke of the applicator  12 , the slide  32  is moved back in the direction of the arrow  6   b  by a sliding block guide (not shown), as disclosed in DE 10 2008 064 559 A1, with the slide causing pivoting of the interlock device  40 , by means of a return section  40   c  of the interlock device  40  counteracting the force of the spring  42 , about the axis  7  in the direction of the arrow  7   b . In this way, the interlock device  40  travels back to its position shown in  FIGS. 2 and 3 , as is evident from  FIGS. 5   a  and  5   b . The first retaining device  50  comprising the permanent magnet  52  holds the interlock device  40  in the first position thus achieved, in the same manner as the retaining member  64 , which is deflected temporarily against the force of the spring  66  when the interlock device attains the first position shown in  FIGS. 5   a  and  5   b  from its second position shown in  FIGS. 4   a  and  4   b  to subsequently come to again bear against the interlock device  40  by way of the contact surface  64   a.    
     Thus the blocked state is again achieved and another blocking period commences, at the end of which the released state can be restored by the user in the manner described. This is represented on the display  19  during the blocked state by the symbol  19   a  being shown in an uninterrupted form. 
     The discharging device illustrated very effectively assures the maintenance of the blocked state, during which no discharging operation is possible. The use of two retaining devices  50 ,  60  greatly reduces the risk of this blocked state being overridden by a single shock to the discharging device and before the blocking period has elapsed. Such a shock may indeed temporarily exceed the retention force of the permanent magnet  52 , but in the case of such a shock, the retaining device  60  is not released due to its spring bias so that the two retaining devices  50 ,  60  re-establish the blocked state once the shock has expired. In order to ensure that the second retaining device  60  is insensitive to shock, a foamed rubber block  80  is provided in the embodiment shown to act as a brake and thus allow the retaining element  62  to be deflected during manual actuation of the actuator  70  but to prevent deflection of the retaining element  62  on the occurrence of a temporary shock. 
     As shown in  FIGS. 5   a  and  5   b , the slide  32  is displaced in the direction of the arrow  6   b  far beyond its position in the blocked state of the blocking device  30 , as shown in  FIGS. 2   a  and  2   b , during its movement in the direction of the arrow  6   b , this relating to the design of the sliding block guide described above and explained in DE 10 2008 064 559 A1. There can be provided an additional damper or brake, for example on the slide  32  itself or also on the bearing of the interlock device  40 , in order, when the actuator  70  is depressed permanently, to prevent the retention force of the first retaining device  50  from being immediately overcome as a result of the reverse movement of the slide  32  in the direction of the arrow  6   a  following the state shown in  FIGS. 5   a  and  5   b.