Paint spraying apparatus

Apparatus for automatic paint spraying, comprising booth means to contain a hazardous atmosphere in which spraying is effected, said booth means being surrounded externally by a non-hazardous atmosphere, said apparatus further comprising a spray gun for directing paint onto an article to be coated, reciprocating means for effecting a reciprocating stroke of said spray gun, valve means operable to control discharge of paint through said spray gun, and automatic control means for controlling the operation of the valve means during the stroke of said spray gun;

• said automatic control means comprising:
• a first part providing programmable control means for determining a desired sequence of operations of said valve means, a second part comprising position indicating means for generating an electrical digital signal representing the position of the spray gun during its stroke, and comparator means for comparing the signal from the position indicating means with reference signals from said programmable control means determining the sequence of operation of said valve means during the stroke and providing an output for use in controlling said valve means in dependence on the position of said spray gun;
• wherein said reciprocating means, valve means and second part of said automatic control means are located within said booth means and the said first part of said automatic control means is located entirely outside said booth means and connected through a suitable interface to the said second part of the automatic control means, whereby said programmable control means is not exposed to said hazardous atmosphere.