Abstract: A connecting pin clip for retaining a solid cylindrical connecting pin in aligned transverse bores in a driving member and paint pump piston, formed out of stainless steel spring wire and having a linear mediate portion connected to two end portions, each of which have a linear section extending generally perpendicularly away from the mediate portion and ending in opposed convex shapes. The clip is resiliently deformable for installation and removal over a portion of the driving member to retain the pin by engagement of the ends of the clip with the ends of the pin which are preferably recessed from the ends of the bore in the driving member.

Abstract: Apparatus for retaining an elongated flexible suction set to a portable paint pump includes a pair of hooks, with one hook extending from a handle of the pump to releasably secure an intermediate portion of a hose of the suction set to the pump and another hook mounted on intermediate portion of the hose to releasably secure a distal end of the hose to the intermediate portion thereof.

Abstract: A valve control mechanism for a paint spraying system provides for pressure relief prior to turn-off of the compressor. A pair of interlocking knobs, a pressure control knob and an off-prime-spray knob, are mechanically interlocked so that the compressor can only be turned on and off in a low pressure condition. When spraying has been completed, it is necessary to first operate the off-prime-spray knob to the prime position at which a cam structure opens the off-prime-spray valve for an immediate pressure relief prior to turn off of the pump.

Abstract: A valve control mechanism for a paint spraying system provides for pressure relief prior to turn-off of the compressor. A pair of interlocking knobs, a pressure control knob and an off-prime-spray knob, are mechanically interlocked so that the compressor can only be turned on and off in a low pressure condition. When spraying has been completed, it is necessary to first operate the off-prime-spray knob to the prime position at which a cam structure opens the off-prime-spray valve for an immediate pressure relief prior to turn off of the pump.

Abstract: There is disclosed herein a liquid spray gun which includes an improved heat dissipation system and an improved leakage flow recirculating system.The improved heat dissipation system results from an improved and stronger air flow through the gun housing and around the electromagnetic coils. The improved air flow is created by a venturi or aspiration effect at the spray tip created by the action of the piston pump in spraying liquid at high velocity reducing the air pressure adjacent the tip. The internal portion of the housing communicates with the low pressure area so air in the housing is drawn from the housing to the low pressure area. Vents are provided in the housing adjacent the electromagnetic coils for outside air to be drawn into said housing over said coils and to the low pressure area, thus improving air flow and heat dissipation.