Abstract: The drive train of the threadably advanced piston for a power caulker is provided with a quick release feature. When this feature is activated, the active portions of the drive nut of a lead screw in the drive train are disconnected from the lead screw so that internal pressure in the supply chamber of the cartridge may quickly equilibrate itself by pushing the piston and its lead screw backwards. Thus, dispensing may be smartly stopped and sharply curtailed, merely by releasing the trigger on the power hand tool and activating the quick release. Either of these acts may be performed first or both may be performed simultaneously. By preference, the quick release feature includes threaded claws that are cammed into and out of driving relation with the lead screw by a simple twist of the drive nut.

Abstract: A rotary power hand tool with a rotary chuck is mated to a push-in piston-type dispensing container of caulking via an adapter which mounts on the tool and is secured to the chuck. The adapter has a plunger provided on the end of a non-rotating screw. When the tool trigger is actuated, a transmission on the actuator is operated to advance the screw and plunger thus advancing the piston of the dispensing container. In the preferred embodiment a peg secured to the drive screw and protruding out of the adapter doubles as a way of preventing the drive screw from rotating and as a way to indicate the relative amount of contents remaining to be dispensed until the container is effectively empty.

Abstract: A container is provided with two chambers, each with a mechanism for expressing its contents toward an outlet neck. The neck mounts a captive cap with an opening through its end wall. A web which longitudinally divides the outlet neck, has an outer tip which is positioned to clean out and close the cap opening as a collar which encircles the captive cap is rotated to axially move the captive cap further onto the container. Rotation of the collar in the angularly opposite sense axially projects the cap so that container contents moving out the neck in the individual lumens can mix where the lumens merge and flow out together through the captive cap outer end opening.