Dispensing device

A dispenser, comprising:

• a housing having a cavity defined therein and having an outlet;
• a piston disposed inside the housing and having at least one retractable catch extending therefrom;
• at least one gear rack capable of translatory motion, the gear rack having teeth capable of engaging with the catch on the piston such that the piston is moved in a first direction when the rack is moved in the first direction, the gear rack capable of rotating into a position where the catch does not engage with the teeth during movement of the gear rack in the first or a second direction;
• a trigger in operative relation to the gear rack such that movement of the trigger causes the rack to move in the first direction and release of the trigger causes the rack to move in the second direction opposite the first direction,
• wherein movement of the gear rack in the second direction causes the catch to retract such that the piston remains substantially in place when the rack moves in the second direction;
• and a cover pivotally attached to the housing at the outlet wherein the cover is mechanically coupled to the gear rack such that opening of the cover causes the gear rack to rotate such that the teeth on the gear rack disengage from the catch on the piston so that the piston can be moved in the second direction for refilling the dispenser.

A dispenser, comprising:

• a cylindrical housing having a cavity defined therein and having a first end with outlet and having a second end disposed opposite from the first end, the housing having a longitudinal axis;
• a piston disposed inside the housing and having at least one retractable catch extending therefrom;
• at least one gear rack disposed in the cavity and wherein the gear rack moves substantially parallel to the longitudinal axis, the gear rack having a plurality of teeth capable of engaging with the catch on the piston such that the piston is moved in a first direction when the rack is moved in the first direction;
• a trigger in operative relation to the gear rack such that actuation of the trigger causes the rack to move in the first direction and release of the trigger causes the rack to move in a second direction opposite the first direction;
• wherein movement of the gear rack in the second direction causes the catch to retract such that the piston remains substantially in place when the rack moves in the second direction;
• a cover pivotally attached to the housing adjacent to the outlet, the cover having an opening defined therein for receiving a portion of a cartridge containing a viscous flowable material, the cover being mechanically coupled to the gear rack such that opening of the cover causes the gear rack to rotate such that the teeth on the gear rack disengage from the catch on the piston such that the piston can be moved in the second direction relative to the gear rack to the second end of the housing for refilling the dispenser.