Dispenser-gun assembly for viscous fluids and dispenser therefor

A dispenser-gun assembly for dispensing a viscous fluid comprising

• a) a dispenser portion comprising;
• i) an elongated tubular barrel member having an elongated cylindrical chamber therein for containing said fluid, said chamber having opposite first and second ends and having a predetermined length;
• ii) nozzle means defining a dispensing nozzle having a reduced dispensing aperture therein, said nozzle means communicating with the first end of said chamber for receiving said fluid therefrom and for dispensing said fluid through said aperture when pressure is applied to said fluid;
• and
• iii) a piston element slidably received in said chamber, said piston element being received in said chamber with an interference fit and being operative for applying pressure to said fluid for dispensing said fluid through said aperture when pressure is applied to said piston element in a direction toward said first end;
• and
• b) a gun portion comprising;
• i) a drive plunger including a drive plunger element receivable in engagement with said piston element for advancing said piston element toward said first end and for thereby applying pressure to said fluid and a drive plunger rod for advancing said drive plunger element in said chamber;
• and
• ii) mechanical advancing means for mechanically advancing said drive plunger in said cylinder toward said first end, said mechanical advancing means being manually operable for mechanically advancing said drive plunger element toward said first end from a first position in said chamber to a second position therein and for normally automatically immediately mechanically returning said drive plunger to said first position unless said drive plunger is manually maintained in an advanced or partially advanced position in said chamber.

A gun for dispensing a viscous fluid from a fluid dispenser of a type including an elongated tubular barrel member having an elongated cylindrical chamber therein for containing said fluid, a nozzle element on one end of said barrel member, said nozzle element defining a reduced dispensing aperture and communicating with said chamber for dispensing fluid therefrom through said aperture and a piston element slidably and sealingly received in said chamber, said piston element being advanceable toward said nozzle element for applying pressure to said fluid, said gun comprising:

• a) a drive plunger including a drive plunger element receivable in engagement with said piston element for advancing said piston element toward said first end and for thereby applying pressure to said fluid and a drive plunger rod for advancing said drive plunger element in said chamber;
• and
• b) mechanical advancing means for mechanically advancing said drive plunger in said cylinder toward said first end, said mechanical advancing means being manually operable for advancing said drive plunger element toward said first end from a first position in said chamber to a second position therein, said drive plunger element normally automatically immediately mechanically returning to said first position unless said drive plunger element is manually maintained in an advanced position in said chamber with said advancing means.