Mastic applicator system

A mastic applicator system comprising a source of mastic, a nozzle for applying the mastic to a surface, and a supply path extending between the source and the nozzle characterized in that the pressure drop in the supply path is varied response to sensed variations in the pressure of the mastic flowing through the nozzle;

• the supply path includes a regulator;
• the setting of the regulator is varied in response to sensed variations in the pressure of the mastic flowing through the nozzle;
• the regulator includes a valving member positioned by controlled air under pressure;
• and the setting of the valving member is varied by varying the pressure of the controlled air.

A mastic applicator system comprising:

• a pump;
• a regulator including a valving member operative to establish a mastic outlet pressure of the regulator;
• a nozzle;
• means establishing a mastic flow path extending from the pump to the regulator and thence to the nozzle;
• a transducer sensing the pressure of the mastic flowing through the nozzle and operative to generate an output signal proportioned to the mastic pressure;
• means generating a command signal;
• a comparator receiving the output signal and the command signal and operative to generate a control signal which is proportioned to the command signal and which is constantly adjusted in response to a sensed differential between the command signal and the output signal;
• and
• means operative in response to receipt of the control signal to vary the setting of the valving member and including means generating a closing force on the valving member proportioned to the mastic outlet pressure within the regulator downstream of the valving member.

A mastic applicator system comprising:

• a pump;
• a regulator;
• a nozzle;
• means establishing a mastic flow path extending from the pump to the regulator and thence to the nozzle;
• a transducer sensing the pressure of the mastic flowing through the nozzle and operative to generate an output signal proportioned to the mastic pressure;
• means generating a command signal;
• a comparator receiving the output signal and the command signal and operative to generate a control signal which is proportioned to the command signal and which is constantly adjusted in response to a sensed differential between the command signal and the output signal;
• and
• a pneumatic valve receiving the control signal and operative to vary the setting of the regulator in proportion to the control signal;
• the regulator defining a flow path through the regulator including a valving member;
• the pneumatic valve being operative to vary the setting of the valving member;
• the regulator including a large area movable member exposed at one face thereof to the output air pressure of the pneumatic valve and a rod secured at its one end to the large area member and at its other end to the valving member;
• the valving member being biased in one direction by the air pressure acting through the rod via the large area member and mastic inlet pressure upstream of the valving member and biased in an opposite direction by mastic outlet pressure downstream of the valving member and a return force acting on an opposite face of the large area member and resisting the movement of the large area member by the air pressure.