摘要 |
A dispenser for dispensing metered amounts of a viscous material includes a rigid tube which defines a compartment for the material, a discharge passage at one end of the tube, a push button activated and reciprocatingly movable rod which moves back and forth between two positions in the tube, and a sealing plunger which moves step-wise on the rod, from the push button end to the discharge end. Each activation of the push button expels a metered amount of the viscous material. The plunger is formed of a short inner tube section which makes sealing contact with the rod, an outer tube section which is in sealing contact with the interior surface of the tube and a radially extending, ring-shaped, rib which connects the two sealing tubes to one another. In a preferred embodiment, the radial cross-section of the plunger exhibits and H-shape. A metallic gripper is secured to the plunger and has a free end which is inclined toward the rod. When the rod is pushed forwardly the gripper bites into the rod causing the plunger to be carried forwardly with the rod to discharge a metered quantity of the viscous material. However, on the backward stroke of the rod, the interengagement with the gripper is lost permitting the plunger to remain in place.
|