Abstract:
An airbrush having a nozzle ( 22 ) through which gas can flow, the end of the nozzle having an inclined surface ( 30 ). The apparatus also includes support means for a liquid source ( 28 ) which, in use, is directed towards the inclined surface of the nozzle.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a Continuation of U.S. patent application Ser. No. 12/300,945 filed on May 8, 2009, which is a National Phase of PCT/GB2007/001852, filed May 17, 2007, which claims the benefit of Great Britain Patent Application No. 0609685.3, filed May 17, 2006, the entire disclosure of which is incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to apparatus for dispensing a tine spray of liquid particles and more especially, but not exclusively, to liquid dispensers known as airbrushes. 
       BACKGROUND OF THE INVENTION 
       [0003]    GB Patent No. 2273065 describes a hand operated pump which can be connected to a liquid dispensing apparatus with the purpose of supplying air under pressure to a liquid source such as a pen with a nib of absorbent material. The hand pump described in that patent is suitable for use with various forms of liquid dispensing apparatus. 
         [0004]    The hand operated pump described in GB 2273065 comprises a bulb of flexible material formed with an open ended neck which locates over the inlet end of the liquid dispensing apparatus. Air enters the bulb via a nozzle in the liquid dispensing apparatus. When the liquid source has been positioned adjacent the nozzle, the flexible bulb is squeezed and the air pushed out onto and over the liquid source directed by the nozzle. When the bulb is released, air is again drawn up through the nozzle of the liquid dispensing apparatus and into the bulb. 
         [0005]    An improvement to the pump of GB2273065 is described in GB2357809. In this arrangement, a separate air inlet is provided. This prevents ink being drawn in back through the nozzle, which may otherwise cause large globules of liquid to be dispensed onto the user&#39;s substrate. 
         [0006]    A disadvantage of the pumps described in GB2357809 is that a relatively high pressure is required in order to obtain sufficient air flow through the nozzle and over the nib to give the desired effect on the apparatus in use. Consequently, the minimum size of the hand-pump is limited which can prevent effective use of the apparatus by young children whose hands are too small to be able to hold and squeeze the hand-pump with sufficient force to provide suitable airflow over the nib. Furthermore, the limitation in the minimum size of the hand-pump provides an apparatus that can appear ungainly and impractical to some potential users. 
         [0007]    These problems are alleviated by the provision of a nozzle with an angled opening in accordance with the present invention. 
       SUMMARY OF THE INVENTION 
       [0008]    In accordance with one aspect of the present invention, there is provided an airbrush apparatus comprising a nozzle, one end of the nozzle having an aperture, and the other end of the nozzle having attached thereto means for providing flow of gas through the nozzle and out of the aperture, the apertured end of the nozzle having an inclined surface with respect to the longitudinal axis of the nozzle, the apparatus further comprising support means for releasably holding a liquid source such as a felt-tipped pen, one end of the liquid source, in use, being directed towards the inclined surface of the nozzle. 
         [0009]    Preferably, the means of providing flow of gas comprises a hand-operated flexible bulb. 
         [0010]    Preferably, the felt-tipped pen is held by the support means such that, in use, the longitudinal axis of the nib of the pen lies generally parallel to the inclined surface of the nozzle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a drawing showing an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    One embodiment of the present invention will now be described, by way of example, with reference to the accompanying FIGURE, which shows a hand operated flexible bulb according to the present invention. 
         [0013]    As can be seen from the FIGURE, the bulb  10  comprises a continuous surface of flexible rubber. To one end  12 , the bulb  10  has an open-ended neck  14 . The other end  16  of the bulb  10  has an aperture  18  which receives an attachment  20  suitably configured to fit within the aperture  18  in an airtight manner. The attachment  20  provides means to connect a further air pump, such as a mechanical or electrical pump (not shown) to the end  16  of the bulb  10 . 
         [0014]    In a further embodiment (not shown) the bulb does not have an aperture to receive any further attachment. 
         [0015]    The neck  14  of the bulb  10  is connected to a first conical nozzle  22 . A second nozzle  24  overlaps the end of the first nozzle  22 . 
         [0016]    The outer surface of the first nozzle  22  has a supporting structure  26  attached thereto that supports and retains a pen  28 , such as for example a felt-tipped pen. Alternatively the pen  28  may comprise a cartridge containing a technical drawing pen, the nib of a conventional pen or a pen like cylindrical container including for example, a dip tube through which a colourant such as ink can be withdrawn. Alternatively, edible food colourants, ink based acrylics and emulsified paints may be dispensed by means of the apparatus. A selection of supporting structures  26  may be provided to enable a variety of different liquid sources to be employed. 
         [0017]    The supporting structure  26  may, of course, be attached to the outer surface of the first nozzle  22 . 
         [0018]    The longitudinal axis of the pen  28  is directed and angled towards the apertured end of the second nozzle  24 . 
         [0019]    The apertured end of the second nozzle  24  is formed with an incline  30  at an angle of between 20 and 60 degrees to the longitudinal axis of the nozzle  24 . Preferably the angle of incline is between 40 and 50 degrees. Preferably still, the angle of incline is 45 degrees. 
         [0020]    The angle of the incline  30  is designed to correspond with the angle of a nib  32  of the pen  28  when the pen  28  is held within the supporting structure  26  during use. At this time, the slope of the incline  30  is generally perpendicular to the direction of a majority part of the nib  32 . In the FIGURE, where the nib  32  is shown to be bullet-shaped, the tip of the nib  32  angles away from the nozzle  24  to form a point. However, the main part of the exposed surface of the nib  32  is held generally parallel to the slope of the incline. 
         [0021]    During use air is directed through the apparatus out of the nozzle  24  and into the exposed side surface of the nib  32 . Expansion of the air occurs right at the tip of the nib  32  forming a fine spray. 
         [0022]    The apertured end of the nozzle  24  with an incline  30  to increase the air flow through the nozzle and over the nib  32  during use. Consequently air can be directed through the apparatus at a lower pressure, which allows the size of the bulb  10  to be substantially reduced and hence more appealing and practical for use by a young child. 
         [0023]    Furthermore, low pressure automatic air pumps, such as electrical pumps can be used to provide air flow through the device. 
         [0024]    In a further embodiment (not shown) the bulb  10  is replaced by a straw which can be blown through to provide the air flow. The inclination  30  of the apertured end of the nozzle  24  provides sufficient air flow over the nib  32  to enable an effective result, even if a simple straw where to be used. 
         [0025]    It will be appreciated that the foregoing is merely exemplary of one embodiment of the pump according to the present invention and of just one form of liquid dispensing apparatus with which it may be used. The skilled reader will understand that modifications can readily be made thereto without departing from the true scope of the invention.