Abstract:
The suggested device comprises a dispensing piston that is actuatable by a pressure medium for dispensing a syringe and a guide portion within which the dispensing piston is displaceably supported. The device is designed for dispensing a double syringe and includes a handling portion for receiving the pressure medium, the dispensing piston, and the guide portion, as well as locking means that are releasable by applying manual pressure to the handling portion and are arranged on the handling portion and operatively connected to locking means provided on the dispensing piston. This allows a very simple repeated use of this arrangement for self-dispensing by patients, and remote wounds, e.g. an arm or foot wound, can also be treated by the patient independently.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a device having a dispensing piston that is actuatable by a pressure medium for dispensing a syringe and a guide portion within which the dispensing piston is displaceably supported. 
         [0002]    A dispensing syringe of this kind with a hypodermic needle is known from U.S. Pat. No. 2,565,081 where the device comprises an actuator that is actuatable by a compression spring and a guide portion within which the dispensing plunger is displaceable. The actuator is held in its tensioned position by a locking catch at its rear end and pressed onto the plunger of the syringe when the locking catch is released. During this operation, the spring expands once. 
         [0003]    U.S. Pat. No. 3,702,608 discloses a dispensing assembly having a portion for receiving a single syringe at its end opposite the outlet and a relatively complicated dispensing mechanism. 
         [0004]    WO 99/37343 also discloses a dispensing assembly that is capable of receiving a single syringe and has a relatively complicated releasing mechanism. 
         [0005]    In the field of wound treatment, besides conventional dressing materials for sterile wound coverage, liquids, pastes, and gelatin are also used which in combination with other substances allow sealing and healing of wounds and pain relief. For this purpose, multicomponent substances are increasingly being used which, however, have to be combined and mixed prior to their application to the wound. To this end, the components are e.g. stored in a double syringe and mixed by means of a static mixer or a spray system prior to their application to the skin or wound surface. Dispensing of the mixture is achieved by applying manual pressure to the plunger of the double syringe. 
         [0006]    Particularly for long-term patients or in the case of chronic wounds, an autonomous wound treatment by the patient is not only desirable but also cost-saving. However, in a conventional double syringe, the dispensing operation requires a force and a certain manual ability of the patient that should not be underestimated. Depending on the location of the wound, it may be difficult for the patient to operate the double syringe. 
         [0007]    Furthermore, a possibility of metering the components to be dispensed is desirable, which is only insufficiently ensured by conventional double syringes. 
       SUMMARY OF THE INVENTION 
       [0008]    On this background, the invention is based on the object of further developing a device of the kind mentioned in the introduction in such a manner that it allows the use of multiple syringes and can be produced inexpensively while ensuring an improved handling by patients. 
         [0009]    Another object of the invention is to allow a repeated use of the device and an accurate metering of any dispensed quantities. 
         [0010]    These objects are attained by a device which is configured to receive and dispense a multiple syringe or cartridge, includes a handling portion for receiving the pressure medium, the dispensing piston, and the guide portion provided with a receiving flange for the multiple syringe, and comprises locking means that are releasable by applying manual pressure to the handling portion and are arranged on the handling portion and operatively connected to locking means provided on the dispensing piston. 
         [0011]    Further preferred embodiments of the invention are defined in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will be explained in more detail hereinafter with reference to drawings of exemplary embodiments, where: 
           [0013]      FIG. 1  shows an exploded view of a first exemplary embodiment of a device according to the invention for automated dispensing of a double syringe; 
           [0014]      FIG. 1   d  shows a perspective view of the assembled device according to  FIG. 1 ; 
           [0015]      FIG. 1   a  shows a perspective view of the handling portion of the device shown in  FIG. 1 ; 
           [0016]      FIG. 1   b  shows a perspective view of the locking sleeve of the device shown in  FIG. 1 ; 
           [0017]      FIG. 1   c  shows a different perspective view of the locking sleeve of  FIG. 1   b;    
           [0018]      FIG. 2  shows a perspective view of a part of the device shown in  FIG. 1  with the dispensing piston in the tensioned position; 
           [0019]      FIG. 3  shows a perspective view of the dispensing piston of  FIG. 1 ; 
           [0020]      FIG. 4  shows a partly sectioned view according to plane IV-IV in  FIG. 2  illustrating the locked position of the dispensing piston in the tensioned piston position; 
           [0021]      FIG. 5  shows a partly sectioned view according to plane V-V in  FIG. 2  illustrating the released position of the locking sleeve; 
           [0022]      FIG. 6  shows a perspective view of a second exemplary embodiment of a device according to the invention with a double syringe for automated dispensing; 
           [0023]      FIG. 7  shows a section according to plane VII-VII in  FIG. 6  in a tensioned position of the dispensing piston; and 
           [0024]      FIG. 8  shows a section according to plane VIII-VIII in  FIG. 6  in a released position of the dispensing piston. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Hereinafter, in the exemplary embodiments, double syringes are depicted and described, but multiple syringes or multiple cartridges having more than two storage containers are also encompassed, in which case the dispensing piston is adapted accordingly. The terms “front” and “rear” refer to the syringe outlet, which is on the front side. 
         [0026]      FIG. 1  shows a first embodiment of a dispensing device  1  according to the invention for a double syringe, comprising a dispensing piston  2 , a guide portion  3 , a spring element  4  that serves as the pressure medium, a handling portion  5 , and a locking sleeve  6 . 
         [0027]    Dispensing piston  2  according to  FIGS. 1 and 3  has the form of a hollow cylinder  8  that is closed at its front end  2   a  by a plunger support  9  and open at its rear end  2   b.  At the front end  2   a  of the external circumferential surface of dispensing piston  2 , a finger rest  7  is provided whose underside extends along a part of the circumference of hollow cylinder  8  and whose plane upper side extends essentially perpendicularly to the circumferential surface of hollow cylinder  8 . Finger rest  7  is insertable in a receiving slot  10  of hollow cylinder  8  and attachable therein, as appears in  FIG. 1  and will be described in more detail in the following description. Along the underside of dispensing piston  2 , a serrated locking toothing  35  is provided. Locking toothing  35  extends over a distance that corresponds to the total stroke of the dispensing piston. In the illustrated position of dispensing piston  2 , the foremost tooth space  35   a  of the locking toothing is located in the axial area of locking catch  30 . The inner side of locking catch  30  has a shape that is equivalent to that of the spaces of the toothing, thereby allowing a positive engagement of locking catch  30  in any one of toothing spaces  35 . 
         [0028]    As appears in  FIG. 1 , guide portion  3  essentially consists of a hollow cylinder  12  whose open end  3   b  is adapted to receive dispensing piston  2 . On the upper side of its circumferential surface, hollow cylinder  12  is provided with an opening  13  that extends over a large part of guide portion  3  longitudinally and whose width essentially corresponds to the attachment area of finger rest  7  on dispensing piston  2  and which further serves for receiving double plunger  55 . In this manner, an axial movement of dispensing piston  2  within guide portion  3  is possible while finger rest  7  protrudes from opening  13 . A forward stop shoulder  34  for locking sleeve  6  is defined by the width of the transversal wall portion along a part of the external circumference of guide portion  3 . 
         [0029]    The piston movement within guide portion  3  is limited by a receiving flange for syringe  15  at front end  3   a  of guide portion  3 . This receiving flange for syringe  15  is in the form of a transversal wall that extends beyond the cylinder diameter on both sides and has a U-shaped recess in its central area in which a double syringe  50  and its double plunger  55  are insertable. On the upper edge of location flange  15 , an insertion opening  16  for the syringe flange of a double syringe is provided, as appears in  FIG. 1 . Thus, during the actuation of double plunger  55 , the forward end position of dispensing piston  2  inside guide portion  3  is attained at the end position point of the double plunger inside the double syringe. 
         [0030]    Spring element  4  is formed of a cylindrically coiled compression spring whose front end  4   a  is arranged in the interior of hollow cylinder  8  in such a manner that its rear end  4   b  protrudes from the open rear end  2   b  of dispensing piston  2 . 
         [0031]      FIG. 1   d  illustrates an assembled device according to the invention with a double syringe  50  and a mixer  53 . The double syringe is actuated by means of a double plunger  55  and further comprises a retaining flange  54  and a thrust plate  57 . 
         [0032]    According to  FIG. 1   a,  handling portion  5  also has an essentially cylindrical shape  18  whose front end  5   a  is open and whose rear end  5   b  is closed by an end wall  19 . In the forward section, the hollow interior of handling portion  5  widens from a stop collar  20  that extends circumferentially along the inner wall. 
         [0033]    Stepped stop collar  20  defines a forward receiving section  33  of handling portion  5  that is configured to receive rearward end section  3   c  of guide portion  3  such that its rear end  3   b  abuts against stepped stop collar  20 . On two opposed sides of the inner wall of receiving section  33 , respective positioning cams  21   a, b  are arranged which extend in the forward direction from stepped stop collar  20 . 
         [0034]    Accordingly, in the rearward end section  3   c  of guide portion  3 , two corresponding positioning slots  22   a, b  are provided, thereby ensuring the correct orientation of guide portion  3  during its insertion into handling portion  5 . On two opposed sides of guide portion  3 , respective snap noses  23   a, b  are arranged on the surface of rearward end section  3   c.  Corresponding snap grooves  24   a, b  are provided along the inner wall of receiving section  33 . In this manner, the assembly of components  3 ,  5  establishes a non-detachable snap connection between snap noses  23   a, b  and snap grooves  24   a, b.    
         [0035]    A cylindrical spring guide  25  is arranged in the central area of the hollow interior of handling portion  5  which essentially extends over its entire length in the axial direction and internally connects to end wall  19 . More specifically, the external diameter of cylindrical spring guide  25  essentially corresponds to the internal diameter of spring element  4 . In this manner, cylindrical spring guide  25  guides rear end  4   b  of spring element  4  toward the inner side of end wall  19 , whereby spring element  4  is compressed during the assembly of components  2 ,  3 ,  4 , and  5 . 
         [0036]    A rearward stop shoulder  26  is arranged along cylindrical surface  18  and circumferentially projects behind receiving section  33 . Specifically, the stop shoulder is located at the front end of end section  5   c  of handling portion  5 . 
         [0037]    According to  FIGS. 1   b  and  1   c,  locking sleeve  6  has an annular sleeve envelope  27  that is slidable over forward end section  5   c  of handling portion  5 . Furthermore, as compared to the external diameter of end section  5   c,  a slightly oval internal diameter of sleeve envelope  27  is provided whose largest dimension is located between the locking catch and the finger rest and allows a corresponding displacement. After its assembly, forward front face  28  of locking sleeve  6  rests against forward stop shoulder  34  of guide portion  3 . In this position, rear end  6   b  of locking sleeve  6  abuts against rearward stop shoulder  26  of handling portion  5 . 
         [0038]    Along the inner wall of sleeve envelope  27 , a locking catch  30  is arranged which extends radially inwards. A lateral aperture  32  that corresponds to locking catch  30  is provided in the forward end section  5   c  of handling portion  5 . Due to the elliptical shape of the internal dimension of the locking sleeve and cylindrical surface  5   c,  it is possible to move locking catch  30  toward lateral aperture  32  during the assembly of components  5 ,  6  and subsequently engage locking catch  30  in lateral aperture  32  so that locking catch  30  projects into the hollow interior of handling portion  5 . 
         [0039]    According to  FIG. 1   c,  an elastic pressure element  31  is arranged on the side of the inner wall of sleeve envelope  27  opposite locking catch  30 . Pressure element  31  causes a force to be applied to locking sleeve  6  in the opposite direction with respect to locking catch  30  in order to bring the latter into engagement with the locking toothing. On the outside of the sleeve, a finger rest  29  is associated to elastic pressure element  31 . By applying pressure to this finger rest, pressure element  31  and thus locking sleeve  6  along with locking catch  30  are disengaged within their radial play from locking toothing  35  on the underside of dispensing piston  2 , thereby releasing the dispensing piston. 
         [0040]    In  FIGS. 4 and 5 , dispensing device  1  is shown in a sectioned view according to planes IV-IV and V-V in  FIG. 2 . In the closed position of locking sleeve  6  shown in  FIG. 4 , finger rest  29  is under the impact of the pressure element and thus, within its radial play, in the remote position from the forward end section  5   c  of handling portion  5 . In this position, the inner side of locking catch  30  extends through aperture  32  into the interior of handling portion  5 . Therefore, locking catch  30  engages in one tooth space of the locking toothing  35  of dispensing piston  2  extending along the inner wall of handling portion  5 . In the rearward end position of dispensing piston  2  shown here, locking catch  30  engages in forward tooth space  35   a.  By the thus formed locking means, dispensing piston  2  is retained in its axial position with respect to handling portion  5  and against the force applied thereto by spring element  4 . 
         [0041]    In the releasing position of locking sleeve  6  shown in  FIG. 5 , finger rest  29  is in a position that results from applying a manual pressure, in which it is displaced with respect to forward end section  5   c  of handling portion  5  within its predetermined play. The serrated inner side of locking catch  30  is thus withdrawn from the interior of handling portion  5 , thereby releasing the locking means. 
         [0042]    When the manual pressure applied to finger rest  29  is cancelled, locking sleeve  6  is returned to the closed position shown in  FIG. 4  by the spring action of pressure element  31 . This causes an engagement thereof in the closest tooth space. Consequently, locking toothing  35  allows dispensing piston  2  to catch with handling portion  5  in different piston positions according to the requirements. 
         [0043]    Manually returning dispensing piston  2  rearwardly is possible from any piston position by applying pressure to finger rest surface  11  of finger rest  7  for the wedge-shaped configuration of locking catch  30  and of locking toothing  35 , respectively, allows a rearward disengagement of locking catch  30  from a tooth space. 
         [0044]      FIG. 6  shows a second exemplary embodiment of a dispensing device  40  according to the invention in a perspective view. Those features which correspond to the first exemplary embodiment are designated by the same reference numerals. Further shown is a double syringe  50  that is suitable for use with dispensing device  1 ,  40 . 
         [0045]    This variant essentially corresponds to the first exemplary embodiment while the main difference consists in a simplified locking and releasing mechanism and the dispensing operation cannot be interrupted. 
         [0046]    Device  40  comprises an elastic finger rest  36  whose rear end  36   b  is rigidly connected to handling portion  5  in the area of its rear end  5   b  and extends forwardly along cylindrical surface  18  up to front end  5   a  of handling portion  5 . At the front end  36   a  of finger rest  36 , a locking catch  37  is arranged. Here, the finger rest with the locking catch essentially has the function of locking sleeve  6  in the first embodiment 1 of the dispensing device. In this embodiment, in contrast to the first exemplary embodiment, locking catch  37  is directed outwardly. 
         [0047]    A locking notch  41  that corresponds to locking catch  37  is provided on dispensing piston  2 . At its front end, dispensing piston  2  has a location slot  10  in which finger rest  7  is insertable. The finger rest has a locking support  42  that extends above hollow cylinder  8  of dispensing piston  2  in the shape of an umbrella. On the underside of locking support  42 , locking notch  41  is arranged, see  FIG. 7 . 
         [0048]    When pressure is applied to pressure surface  38  of finger rest  36 , locking catch  37  is depressed and disengages from locking notch  41 . Due to the spring arm configuration of finger rest  36 , locking catch  37  is returned to its initial position when the manually applied pressure is cancelled while the wedge shape of locking catch  37  ensures its engagement in the rearward position when the appliance is reused at a later time. 
         [0049]      FIGS. 7 and 8  show sectioned perspective views of guide portion  2  according to section planes VII-VII and VIII-VIII in  FIG. 6  in the tensioned and released positions. 
         [0050]    From the description of the exemplary embodiments, various modifications are accessible to those skilled in the art without departing from the protective scope of the invention, which is defined by the claims. Thus, a locking toothing may also be provided with external locking means according to the second exemplary embodiment. In this manner, by simply canceling the manually applied pressure, it is possible to lock the dispensing piston in a locking means at any time during dispensing. Furthermore, locking means may be provided which comprise a locking catch on dispensing piston  2  and a locking toothing on handling portion  5 . It is further possible to provide an external locking means in the form of a locking catch on a locking sleeve or an internal locking means in the form of a locking bracket on the handling portion. Also, instead of a compression spring, a compressed air cartridge or other such pressure medium may be used as a pressure medium to facilitate self-dispensing.