Abstract:
The present invention relates to a delivery device for delivering predetermined amounts of fluid, comprising a body ( 10 ), a container ( 16 ) filled with fluid to be delivered arranged inside said body, said container comprising an opening for expelling said fluid and a wall ( 18 ) movable inside said container ( 16 ), a threaded plunger rod ( 46 ) arranged movable inside said body ( 10 ) in the longitudinal direction and in contact with said movable wall ( 18 ), a manually operated push means ( 14, 60 ) movable in the longitudinal direction capable of, upon operation, move said plunger rod ( 46 ) towards said movable wall ( 18 ), thereby expelling fluid, and means for transforming a generally linear movement of said push means ( 14, 60 ) to a rotational movement of said plunger rod ( 46 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a delivery device and in particular a medical delivery device. 
       BACKGROUND ART 
       [0002]    There are numerous different types of delivery devices on the market and even more delivery devices that have been developed but have not reached any market. The devices display different degrees of automation and functions depending on the particular demands and requirements. 
         [0003]    The delivery devices range from dispensers for cosmetic products to medical delivery devices for administering vital drugs, such as injectors, inhalers and nebulisers, where many are quite advanced. With the advanced functions comes the necessity for rather complex mechanical solutions requiring a large number of components that have to be able to interact with each other in a reliable and safe way, in particular when dealing with vital drugs. 
         [0004]    This in turn means that the cost of the devices becomes rather high and there is further a risk that the advanced functions requires complex handling steps in order to operate the device for administering a drug dose. For a number of persons that use this type of device, the complexity may be too much, leading to improper handling of the device, which in turn could lead to serious consequences. 
         [0005]    For some types of application, the device need not be so advanced or it could be that the cost of the device needs to be kept as low as possible, but still needs to have a decent functionality. Another aspect when dispensing of fluids is the tendency of drooling after a dose has been delivered. This is quite common for some types of delivery devices because of the “resiliency” of the system, such as residual tension in springs, in rubber stoppers inside cartridges and the like. 
         [0006]    The document EP 1 547 694 deals with a dispenser solution where the focus is on low manufacturing and filling costs. It comprises an outer casing and a fluid insert where the fluid insert is moved between two positions for dispensing a dose. This solution is obviously very cost-effective but the handling functionality is not optimal. It has further no means for preventing drooling of fluid after delivered dose. There is thus a need for a cost-effective delivery device that also comprises a good functionality. 
       DISCLOSURE OF INVENTION 
       [0007]    The aim of the present invention is to remedy the drawbacks of the state of the art devices described above. 
         [0008]    This aim is solved by a delivery device according to the independent patent claim. Preferable embodiments are the subject of the dependent patent claims. 
         [0009]    According to a main aspect of the invention it is characterised by a delivery device for delivering predetermined amounts of fluid, Delivery device for delivering predetermined amounts of fluid, comprising a body, a container filled with fluid to be delivered arranged inside said body, said container comprising an opening for expelling said fluid and a wall movable inside said container, a threaded plunger rod ( 46 ) arranged movable inside said body in the longitudinal direction and in contact with said movable wall, a manually operated push means movable in the longitudinal direction capable of, upon operation, move said plunger rod towards said movable wall, thereby expelling fluid, and means for transforming a generally linear movement of said push means to a rotational movement of said plunger rod, wherein said transforming means comprises a first set of surfaces arranged to said manually operated push means inclined with respect to the longitudinal direction co-acting with a second set of inclined surfaces arranged on a rotatable drive means rotatably locked to said plunger rod. 
         [0010]    According to another aspect of the invention, said second set of inclined surfaces are arranged around the circumference of the drive means having a predetermined number of degrees to each other corresponding to the predetermined amount of fluid to be delivered. 
         [0011]    According to a further aspect of the invention, said drive means is arranged with a ratchet interface co-operating with a fixed ratchet interface arranged on the body for preventing a return movement of said drive means. 
         [0012]    According to yet an aspect of the invention, the device further comprises means capable of unlocking said push means between a position where said push means are locked from being manually operated in the longitudinal direction to a position enabling operation. 
         [0013]    According to another important aspect, the device further comprises a dose delivery means attached to the opening of said container wherein a closing valve is arranged to open above a certain pressure inside said container and to close below said pressure. 
         [0014]    The present invention displays a number of advantages. The use of a push means that is manually operable in a linear manner is easy and convenient for the user to handle at the same time as a rotational movement for applying pressure to a fluid for expelling it means a better utility of the manual force from the user, because for many fluids a linear manual force is too low for expelling a fluid through an opening in the container. This is especially the case for fluids with high viscosity. 
         [0015]    Preferably the transformation from linear movement to rotational movement is performed with inclined surfaces such as ramps and ratchet interfaces which are simple and cost-effective to manufacture with few components. 
         [0016]    By varying the inclination of the ramps and the pitch of the threads it is possible to adjust the quantity of the delivered dose and to set the force required to deliver said dose in a simple and effective way. 
         [0017]    Preferably the device is arranged with a valve at the delivery opening for preventing drooling at the end of delivered dose. Because the valve preferably is opened and closed by the pressure from the delivered fluid a reliable opening and closing of the valve is obtained at start and end of dose delivery. 
         [0018]    The device could also be arranged with dose delivering units such as injection needles, aerosol nozzles and nebulising nozzles for different types of application, drug containers and use. 
         [0019]    These and other aspects of and advantages with the present invention will become apparent from the following detailed description and from the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0020]    In the following detailed description of the invention, reference will be made to the accompanying drawings, of which 
           [0021]      FIG. 1  is a perspective view of one embodiment of the present invention, 
           [0022]      FIG. 2  is another perspective view of the embodiment of  FIG. 1 , 
           [0023]      FIG. 3  is a cross-sectional side view of one embodiment of the present invention, 
           [0024]      FIGS. 4 to 6  are detailed views in cross-section of the rear part of the embodiment of  FIG. 1 , 
           [0025]      FIG. 7  is a detailed view in cross-section of the front part of the embodiment of  FIG. 1 , 
           [0026]      FIG. 8  is a view in cross-section of a component comprised in the embodiment of  FIG. 1 , 
           [0027]      FIG. 9  is a perspective view of another component of the embodiment, 
           [0028]      FIG. 10  is a perspective view of a further component, 
           [0029]      FIGS. 11 a  and 11 b    are perspective views of yet a component of the embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    The device according to the present invention is shown in the drawings. The device comprises an elongated body  10  having a front end and a rear end,  FIGS. 1 and 2 . The front end is in the storage and pre-use state arranged with a removable cap  12 . The rear end is arranged with a protruding button  14 , hereafter named thumb button, the function of which will be described below. 
         [0031]    As seen in  FIG. 3  a container  16 ; e.g. a cartridge, a syringe, a cream container, a gas container; comprising fluid to be delivered is inside the body. A movable wall  18  is arranged inside the container. At the front end of the container an end piece  20  is attached, for example by a cylindrical part  22  having outwardly directed grooves and/or protrusions  24  mating with inwardly directed grooves and/or protrusions  26  of a cylindrical part  28  of the container.  FIG. 7 . 
         [0032]    The end piece is arranged with a central opening  30 , through which the fluid may be expelled. A valve  32  is arranged in the vicinity of the central opening, arranged with a front part having a shape corresponding to the central opening. A valve resilient means  34 , e.g. a spring, arranged between the valve and the container urges the valve into the central opening. A passage  36  is arranged between the interior of the container and a space  38  between the valve and the end piece, delimited by an annular surface  40  of the valve on the opposite side of the valve resilient means. 
         [0033]    The body  10  is further arranged with a central passage  42  arranged with threads  44  and ramps  52 ,  FIG. 8 , through which a threaded plunger rod  46  is arranged. A generally cylindrical part, hereafter named driver  48 ,  FIG. 10 , is arranged adjacent the threaded passage. The plunger rod extends through the driver in a rotationally locked, but slidable manner with the help of a spline design. The front end surface of the driver is arranged with a ratchet interface having inclined ramps  50  co-acting with a surface surrounding the central passage with corresponding ramps  52  of the body  10 ,  FIG. 8 , the function of which will be described below. A rear end  54  of the driver has a somewhat larger diameter and is arranged with a number of outwardly directed protrusions  56  on its circumference, where the rearwardly directed surfaces  58  are somewhat inclined. In the shown embodiment there are three protrusions arranged 120° to each other around the circumference. 
         [0034]    The driver  48  is co-acting with a further generally cylindrical part, hereafter named toggle sleeve  60 ,  FIGS. 11 a  and  b   . The front end of the toggle sleeve is arranged with a circumferential ledge  62  having a number of cut-outs  64 , which mate with longitudinal ridges  66  on the inner surface of the body  10 ,  FIG. 8 . At the inner walls of the toggle sleeve inclined ridges  68  are arranged, which cooperate with the inclined surfaces  58  of the protrusions  56  of the driver  48  in a manner that will be explained. 
         [0035]    The rear end surface  70  of the toggle sleeve  60  is arranged with inclined surfaces  72 , which surfaces co-act with corresponding surfaces  76  of a tubular part  78  of the thumb button  14 ,  FIG. 9 . The thumb button is arranged with a front cylindrical part  80  inside the body and is prevented from moving rearwardly by a circumferential ledge  82  in contact with an inwardly directed ledge  84  of the body  10 . The front cylindrical part of the thumb button is further arranged with longitudinal grooves  86  arranged with a pitch and a width corresponding to the longitudinal ridges  66  of the body  10 . In a first embodiment, the front end surface of the thumb button, shown in  FIG. 9 , is arranged with a number of inclined surfaces  88  and stop ledges  90 . In a second embodiment, the perimeter surface of the thumb button is further arranged with a release button as e.g. a bump, not shown, which is capable of interact with a respective through hole or indentation, not shown, on the perimeter surface of the body  10  at its rear end. Moreover, a resilient means  92 , e.g. a spring, is arranged between an inner surface of the thumb button and the rear end of the driver. 
         [0036]    The device is intended to function as follows. When the device is delivered to the user, the end cap  12  is on and held in place by an annular ledge  94  on the outer surface of the container cooperating with an annular groove  96  on the inner surface of the cap. The cap is removed by pulling it off the device. The thumb button is in the locked position,  FIG. 4 . The next step is to enable delivery of fluid. In the first embodiment, the thumb button  14  is unlocked by being turned until the stop ledges  90  on the front end surface come in contact with the ridges  66  of the body. In the second embodiment, the thumb button  14  is unlocked by pressing the release button whereby the thumb button is ejected towards its rear end and forced to turn until the stop ledges  90  on the front end surface come in contact with the ridges  66  of the body due to the pressure exerted by the spring  92 . The inclined surfaces  72  of the toggle sleeve  60  and the mating surfaces  76  of the thumb button  14  serve the purpose of holding the thumb button in the “closed” and “open” positions as well as providing tactile feedback to the user. In the open position the ridges  66  are aligned with the grooves  86  of the thumb button, thereby enabling the thumb button to be pushed into the body, i.e. enabling use of the device for delivery of fluid,  FIG. 5 . 
         [0037]    The pressing of the thumb button causes the toggle sleeve  60  to move forward,  FIG. 6 . This in turn will cause the driver  48  to rotate because of the inclined ridges  68  of the toggle sleeve acting on the end surfaces  58  of the protrusions  56  of the driver. The rotation of the driver is transmitted to the plunger rod  46  because of the rotational lock between them, and due to the threads of the plunger rod cooperating with the threads of the body; the plunger rod will move forward and thus press the movable wall  18  towards the front end of the device. 
         [0038]    The pressure from the movable wall will press the fluid through the passage  36  in the end part of the container and then act on the annular surface  40  of the valve  32 . This pressure will cause the valve to open against the force of the valve resilient means  34 , thereby expelling the fluid through the central opening  30 . As soon as the pressure from the fluid decreases below the force of the valve resilient means, the valve will close, thereby preventing any drooling of the fluid. 
         [0039]    When the driver has rotated about 120° the ratchet interface between the driver and the body is such that the ramps  50 ,  52  falls into the next indexed position and the dose is completed. The ramps providing the indexed positions prevent any backdriving of the driver. When the user releases the pressure on the thumb button, the force from the resilient means  92  will force the toggle sleeve back to its original position in the longitudinal direction. In order for the inclined ridges  68  of the toggle sleeve to be able to act on the protrusions  56  of the driver for subsequent delivery, the toggle sleeve has to be slightly rotated which is done with the ramps  72  on the rear end of the toggle sleeve working with the mating ramps  76  on the thumb button. In that respect the cut-outs  64  on the toggle sleeve are made somewhat wider than the ridges  66  of the body to permit this slightly rotation. 
         [0040]    Preferably the device is primed before the first use. This is done by holding the device with the front end pointing upwards and by pressing the thumb button a number of times. 
         [0041]    It is to be understood that the device can be modified in many ways. Even though a rotation of 120° has been described, other pitches may be chosen depending on for example the dose quantity. In that respect the number of degrees to each other of the second set of inclined surfaces arranged around the circumference of the drive means may be modified and the pitch of the threads may also be modified to provide different lengths that the plunger rod is moved, thus providing different dose quantities. 
         [0042]    It is further to be understood that the device may be provided with different delivery means such as injection needles attached to the front end of the container for enabling injection of fluid, spray nozzles when the device is to be used as inhaler or nebuliser. 
         [0043]    In this respect it is to be understood that the embodiment described above and shown in the drawings is to be regarded only as non-limiting example of the invention and that it may be modified in many ways within the scope of protection by the patent claims.