GB2257058A - Airbrush - Google Patents

Abstract

An airbrush has a reservoir pen with a nib of absorbent material which is detachable from the main body so that fluid changes or replacements are possible. A sliding nozzle 5 determines the ratio of air to fluid by controlling the air velocity due to changes in the cross sectional area of the air passage relative to the nib. Fluid flow through the reservoir is enabled by relieving the vacuum behind the fluid by means of a small hole in the end cap. The sliding of the nozzle and control of the airflow are achieved in one, finger tip control. Nozzle (5) is e.g. a Venturi shaped cone attached to the main body by a sliding seal (6). <IMAGE>

Description

AIRBRUSH This invention relates to an airbrush.

Airbrushes are widely used in industrial and artistic applications for the covering of a given surface with a choice of colouring or coating mediums or other such liquids hereafter referred to as fluid or fluids. There are many forms of airbrush but almost all use a fine needle to control the mixing ratio of fluid to air.

Airbrushes using this form of mixing are expensive due to the fine tolerances required in the manufacture of the unit.

According to the present invention there is provided an airbrush comprising a removable, internally held pen reservoir with à nib of absorbent material and a hole in the rear of the pen body, a main outer body to house the pen through which compressed air is blown, a releasable nozzle and means for an airtight sliding seal linking the main outer body to the nozzle.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which:- Figure 1 illustrates the pen detached and separate from the main housing.

Figure 2 illustrates the pen in position in the main outer body.

Figure 3 illustrates the nozzle attached and in its inner position.

Figure 4 illustrates the nozzle attached and in its outer position.

Referring to the drawing the airbrush comprises a changeable pen 2 with a nib of an absorbent material 1 and an end cap or lid 3 with a small diameter hole in its end, as shown in Fig 1. The pen is then inserted into the main housing 4 and by means of a simple catch (not shown) is held in place as seen in Fig 2. The venturi shaped nozzle 5 is then attached to the end of the main body by means of an airtight sliding seal 6.

The airbrush works by blowing compressed air through the main outer body, around the outside of the pen and past the nib. When the air stream flows past the nib it picks up particles cf fluid and carries the air and fluid mixture to the nozzle where it emerges as a spray; The hole in the pen cap equalizes the pressure inside the pen reservoir thus avoiding a vacuum and allowing fluid to flow.

The ratio of liquid to air can be controlled by sliding the nozzle in relation to the nib.

In Fig 3 the-nozzle is in its inner position and the passing air has a relatively small cross sectional area in which to travel, its velocity therefore increases. As the velocity increases more fluid is introduced to the airstream hence a denser spray emerges.

In Fig 4 the nozzle is moved to its outer position and the passing air has a larger cross sectional area in which to travel, its velocity decreases and less fluid is introduced to the spray.

With the correct dimensions it is possible to completely eliminate fluid introduction to the airstream. There is provided means for independently controlling the sliding nozzle and amount of air supplied in one finger control.

Claims (4)

1 An airbrush comprising a removable internally held pen reservoir, with a nib of absorbent material and a hole in the rear of the pen body, a main outer body to house the pen through which compressed air is blown, a releasable nozzle and means for an airtight sliding seal linking the main outer body to the nozzle.

2 An airbrush as described in Claim 1 wherein the nozzle consists of a venturi shaped cone.

3 An airbrush as claimed in Claim 1 or Claim 2 wherein means for controlling the sliding of the nozzle and amount of air introduced are controlled by one finger.

4 An airbrush substantially described herein with reference to Figures 1-4 of the accompanying drawing.