Manually-operated spray applicator

A manually-operated spray applicator for discharging a coating fluid residing therein by propelling said fluid as a spray from an outlet port with an airjet issuing slightly upstream thereof and created upon the manual stroke of an air-compression piston, said applicator comprising:

• (a.) receiving chamber means wherein a coating fluid is contained, having an inlet port for admitting a quantity of said fluid thereto and an outlet port for discharging a portion thereof;
• (b.) a closed compression chamber, having sidewalls and opposed end walls, receiving a manually-operated air-compression piston having a stroke length defined generally between said end walls;
• (c.) stroke-responsive sealing stem means having a central airway with an airjet orifice at the distal end thereof in registration with said outlet port and communicating at its proximal end with said compression chamber, said stem means being reciprocalbe in response to the location of said air-compression piston along the stroke length thereof, from a biased sealing position wherein said stem means is in sealing engagement with said outlet port to a spray discharge position wherein said stem is retracted and said airjet orifice is disposed within said receiving chamber slightly upstream of said outlet port;
• and,
• (d.) valve means for confining airflow through said central airway substantially to unidirectional airflow from said proximal end to said distal end upon a compression/return stroke cycle of said air-compression piston.

A manually-operated spray applicator for discharging a coating fluid residing therein by propelling said fluid as a spray from an outlet port with an airjet issuing slightly upstream thereof and created upon the manual stroke of an air-compression piston, said applicator comprising:

• (a.) receiving chamber means wherein a coating fluid is contained, having an inlet port for admitting a quantity of said fluid thereto and an outlet port for discharging a portion thereof;
• (b.) a closed compression chamber having sidewalls and opposed end walls, receiving a manually-operated air-compression piston having a stroke length defined generally between said end walls;
• (c.) stroke-responsive sealing stem means having a central airway with an airjet orifice at the distal end thereof in registration with said outlet port and communicating at its proximal end with said compression chamber, said stem means being reciprocable in response to the location of said air-compression piston along the stroke length thereof from a biased sealing position in engagement with said outlet port to a spray discharge position, wherein said stem is retracted and said airjet orifice is disposed within said receiving chamber slightly upstream of said outlet port;
• (d.) spray control means for reciprocating said stem means in response to the location of said air-compression piston along said stroke length, said spray control means first retracting said stem means to said spray discharge position and then returning said stem means to said sealing position intermediate the length of said stroke, whereby said stem means is in said sealing position at the beginning and end of each stroke of said air-compression piston, said spray control means including a spray control piston means in operative engagement with said stem means, whereby reciprocation of said control piston within said control chamber causes reciprocation of said stem means, and a spray control airway providing communication between said control chamber and said compression chamber through a spray control port located in said sidewall of said compression chamber at a preselected distance along said stroke length corresponding to the stroke-responsive return of said stem means near the end of said stroke;
• wherein depression of said air-compression piston creates a pressure head within said control chamber having a force in excess of the biasing force on said stem means thereby reciprocating said stem means to said spray discharge position and further wherein continued depression of said air-compression piston beyond said spray control port permits venting of said pressure head and return of said stem means to said sealing position prior to the end of said stroke;
• (e.) spray adjustment means for controlling discharge of coating fluid from said outlet port, comprising stem retraction control means including a stop ring in adjustable, cooperative engagement with said stem means within said control chamber for regulating the depth of retraction of said stem means and lever means extending outwardly from said stop ring for positioning said stop ring at a preselected location within said control chamber.