GB2276571A - Powder feed venturi device for electrostatic spray guns - Google Patents

Abstract

An electrostatic spray powder feed venturi device for connecting to the hose of an spray gun comprises an inlet tube through which air or gas enters the device, from there the air/gas is forced to a ball vibrator (which comprises a metal ball enclosed in a metal chamber) causing the ball to revolve at high speed and produce vibrations, the air/gas exhausts from the vibrator are lead to a 'T' junction which produce two jets of air/gas, these lets cause a suction at the powder pick-up orifice on the device, the powder after travelling through a tube in the device enters the hose of the spray gun. <IMAGE>

Description

IMPROVEMENTS TO AN ELECTROSTATIC SPRAY POWDER FEED VENTURI SYSTEM This invention relates to an insertion device that requires no agitation to a box of powder paint which is then sprayed electrostatically.

Conventional electrostatic powder spray equipment requires a hopper container for the storage of the powder paint, with an attached venturi or pump to propel the powder from the hopper to the spray gun via a hose. Alternatively, to spray directly from the manufacturers box of powder, an insertion venturi or pump is inserted directly into the box of powder to suck the powder from the box, This causes cavitation and caving creating powder starvation. To overcome this, it is necesssary to place the box of powder on an agitated base.

According to the present invention there is a small device through which regulated compressed air or gas is fed via a tube into a Jet that propels a ball at high speed centrifugally, causing a vibration.

The device is placed directly into the box of powder paint. The exhaust air is then fed to two jets - one which causes a suction to suck up the powder and the other jet to cause a disturbance in the powder that allows the device to bury itself. This single jet may also be made into a multitude of small jets, depending on the type of powder being used.

A combination of the jet disturbance and vibration ensures a continuous flow of powder from the main Jet without caving or cavitation. The invention enables rapid colour change, and a cleaner environment for the spray operator.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in perspective the device.

Figure 2 illustrates the compressed air or gas inlet.

Figure 3 illustrates the connector for powder hose to spray gun.

Figure 4 illustrates the steel ball.

Figure 5 illustrates the exhaust air or gas from the vibrator to the two jets.

Figure 6 illustrates the vibrator casing for the steel ball.

Figure 7 illustrates the jet for the device to bury itself.

Figure 8 illustrates the jet to propel powder through the hose to the powder gun.

Figure 9 shows the powder being sucked into the air/gas stream.

Figure 10 illustrates the powder pick-up orifice.

Figure 11 shows how the case may be resin, metal, plastic or wood - or a mixture of any material mentioned.

Figure 12 illustrates the one way ball valve.

Referring to the drawing the device comprises of an air/gas intake which is a rigid metal pipe which feeds directly into a metal casing (Figure 6). This propels a ball centrifugally at high speed, causing vibration.

The air/gas exhausts from the vibrator via a tube. This is then connected to a T-junction (Figure 5) which feeds air/gas to the two jets (Figures 7 and 8).

The air/gas causes a suction on the orifice (Figure 10). The air/gas and powder mixture exits the connector (Figure 3) to a hose which in turn conveys the powder to the spray gun. As the powder is sucked away the small jet (Figure 7) enables it to bury itself, The smaller sprung loaded ball (Figure 12) is a safeguard against powder being blown backwards into the vibrating casing chamber causing inferior performance when being cleaned with compressed air.

Figure 1 shows the device in an operating mode as the small ball (Figure 12) is being forced downwards.

Claims (3)

1 A single air/gas source that propels a ball centrifugally causing vibration and propels powder to a spray gun and also enables the device to bury itself.

2 A jet of air/gas mixture that passes through the centre of the centrifugal vibrator1 enabling the device to be narrow in width in order that it may be able to sink into the powder with less resistance.

3 A small Jet of air that enables the device to bury itself.