Material dispensing tool and plunger for cylindrical cartridges

A tool for dispensing material from two tubular cartridges each having a front closure wall with a nozzle and having an open rear end, a wiper slidable within the cartridge and closing the open end thereof, and a static mixing nozzle sealed over the cartridge nozzles and having a common outlet for the mixed cartridge materials, comprising the combination of

• means for supporting the separate cartridges in tangentially contacting parallel side-by-side relationship, a plunger sized to fit within the open end of each cartridge and against the wiper, an elongated rod supporting each plunger for axial movement within the cartridge, and a connecting member between the plunger rods allowing them to move only in unison;
• a rear wall adjacent the open ends of the cartridges, a power mechanism on the rear wall and having a stationary handle and a movable trigger, and an elongated drive rod operatively coupled between the trigger and the connecting member, whereby trigger activation drives said drive rod and plungers in the direction toward the front closure walls;
• and
• the plunger rods being in parallel side-by-side relationship and defining a plane extended through the cartridges generally where tangentially contacting, the drive rod being parallel to said plunger rods and aligned generally on said plane, minimizing offset couples generated between the plunger and drive rods, and being cantilevering forwardly beyond the rear wall and telescoping into one of the open cartridge ends upon trigger activation.

A tool for dispensing material from two tubular cartridges each having a front closure wall with a nozzle and having an open rear end, a wiper slidable within the cartridge and closing the open end thereof, and a static mixing nozzle sealed over the cartridge nozzles and having a common outlet for the mixed cartridge materials, comprising the combination of

• means for supporting the separate cartridges in parallel side-by-side relationship, a plunger sized to fit within the open end of each cartridge and against the wiper, an elongated rod supporting each plunger for axial movement within the cartridge, and a connecting member between the plunger rods allowing them to move only in unison;
• a rear wall adjacent the open ends of the cartridges, a power mechanism on the rear wall and having a stationary handle and a movable trigger, and an elongated drive rod operatively coupled between the trigger and the connecting member, whereby trigger activation drives said drive rod and plungers in the direction toward the front closure walls;
• the plunger rods being in parallel side-by-side relationship and defining a plane extended through the cartridges, and the drive rod being parallel to said plunger rods and aligned generally on said plane, minimizing offset couples generated between the plunger and drive rods;
• and
• each of said plungers having a body with rear and front peripherical surfaces, rear and front radial shoulders at adjacent ends of the perpherical surfaces, and a conically ramped surface expanding from its smallest adjacent the front shoulder to its largest adjacent the rear shoulder;
• and an O-ring surrounding the ramped surface and movable between the radial shoulders, and said O-ring and ramped surface being sized with the O-ring against the rear shoulder operable to seat between the cartridge and ramped surface for sealing against rearward material leakage therepast and being sized with the O-ring against the front shoulder to be gapped from between the cartridge and ramped surface for cartridge venting and rearward plunger withdrawal from the cartridge.